darshan institute of engineering & technology rajkot€¦ · bm dbm sdbc bc 1 deleterious...

DARSHAN INSTITUTE

OF

ENGINEERING & TECHNOLOGY

RAJKOT

HIGHWAY ENGINEERING

(2150601)

LAB MANUAL

DEGREE CIVIL ENGINEERING

SEMESTER – V

Name of student

Roll No

Enrollment No

Class

A.Y. 2019-2020

Department of Civil Engineering, Darshan Institute of Engineering and Technology-RAJKOT

Highway Engineering Lab Manual (2150601)–Sem.-V Civil Engineering Page 1

INDEX Sr. No. Name of Experiment Date Page Marks Sign.

SECTION-A –TEST ON AGGREGATES

1 Shape Test (Flakiness Index + Elongation Index) (IS:2386 Part-1)

2 Aggregate Impact Test (IS:2386 Part-4)

3 Aggregate Crushing Test (IS:2386 Part-4)

4 Specific Gravity and Water Absorption Test (IS:2386 Part-3) 5 Aggregate Los Angeles Abrasion Test (IS:2386 Part-4) 6 Gradation and Blending of Aggregate (IS:383-2016)

SECTION-B –TEST ON SOIL (Subgrade)

7 California Bearing Ratio Test-CBR (IS:2720 Part 16 - 1987) 8 Dynamic Cone Penetrometer Test-DCP (IRC: SP:72-2015)

SECTION-C –TEST ON BITUMEN AND BITUMINOUS MIX DESIGN

CONSISTENCY TESTS OF BITUMEN

9 Penetration test (IS:1203-1978) 10 Softening point test (IS:1205-1978) 11 Introduction of tar viscometer (IS:1206 Part 1 - 1978)

12 Viscosity test- Absolute Viscosity (IS:1206 Part 2 - 1978)

13 Viscosity test – Kinematic Viscosity (IS:1206 Part 3 - 1978)

AGING TESTS ON BITUMEN

14 Introduction on Thin film oven test (ASTM-D-1754/IS:9283)

SAFETY TESTS ON BITUMEN

15 Flash and Fire point test (IS: 1209-1978)

OTHER TESTS

16 Specific Gravity test on bitumen (IS: 1202-1978)

17 Ductility test (IS: 1208-1978)

SECTION-D –TEST ON BITUMINOUS MIX

18 % Bitumen content in Paving mixture (IRC: SP: 11 - 1988)

19 Stripping value test (IS:6241 - 1971)

20 Marshal Stability Test-Determination of O.B.C. (MS-2 7th Edition)

SECTION-E DESIGN OF CONCRETE MIX FOR PAVEMENT 21 Design of concrete Mix for PQC (IRC: 44-2008)

SECTION-F- A STUDY ON TRAFFIC PARAMETERS 22 Spot speed study

23 Traffic Volume Study

24 Accident Study

SECTION-G- HIGHWAY GEOMETRIC DESIGN 25 Highway Geometric Design (IRC:73-1980 & IRC:86-1983)

SECTION-H- FIELD TESTS ON PAVEMENT LAYERS

26 Determination of Field Density of Pavement Layer (IS: 2720 Part 28 &

Part 29 - 1974)

27 Introduction of Plate Bearing Test (IS:9214-1979)

28 Introduction of Benkelman Beam Deflection (IRC:81-1997)

29 Introduction Unevenness Measurement by Bump Integrator and MERLIN (IRC: SP: 16-2004 & IRC: 82-2015)



Laboratory Instructions

1. Study the experiment and read in detail aim, apparatus, and procedure of each

experiment before coming to the lab. The lab teachers are instructed to take a brief

written test on experiment performed in previous laboratory session for about 5-10

minutes before the commencement of the new experiment.

2. After the test, the lab teacher will give instruction to start the new experiment. Do

the experiment and note the readings as a group.

3. After you complete the experiment, you must do the calculations and discussion of

results by yourself before leaving the lab.

4. Ensure that lab teacher have checked your results, put up marks in manual and

signed your work

5. Follow all the safety instructions given by the Lab staff. Kindly wear shoes inside

the laboratory

6. Absence in laboratory session will be taken very seriously including fail grade as

per rules. No compensatory experiments will be allowed.

7. Tests shall be done in groups. However, observation table, calculation, Discussion

of the result, etc. should be individual and should be completed on the same day.

8. Return the equipment after the test to the lab teacher.

9. Lab teacher shall supervise the experiment and marks will be awarded based on

the participation in the experiments, and the report.

Student’s Signature



HIGHWAY ENGINEERING

Pavement Design Data

Required

Standard

Guideline Software

Test on

Material

Fle

xib

le P

avem

ent

Th

ickn

ess

• Traffic census

• Subgrade CBR

• Axle load

spectrum

• Vehicle damage

factor

• Resilient

Modulus

IRC: 37-2018 IITPAVE

Tests on soil

• Soil

classification

• CBR

• Index properties

Mat

eria

l

Mix

ture

Physical

properties of

Aggregate &

Bitumen

MS-2

Asphalt Mix

Design

Methods (7th

Edition)

Microsoft

Excel

Tests on

Aggregate &

Bitumen

Rig

id P

avem

ent

Th

ickn

ess

• Traffic census

• Modulus of Sub-

Grade

• CBR

• Axle load

spectrum

IRC: 58-2015 IITRIGID

Tests on soil

• Soil

classification

• Plate load test

• Index properties

Mat

eria

l

Mix

ture

Physical

properties of

Aggregate &

Cement

IRC: 44-2008 Microsoft

Excel

Tests on

Aggregate &

Cement

Load

Distribution: Rigid Pavement Flexible Pavement



Components of Flexible Pavement

Components of Rigid Pavement



AGGREGATE TEST VALUE ACCEPTANCE CRITERIA

AGGREGATE SPECIFICATION FOR VARIOUS TYPE OF ROAD CONSTRUCTION ACTIVITIES (As per IS/ IRC/ MoRT&H 5th Rev.)

Sr. No

Property Name of Test IS Code

Granular Sub-Bases, Base courses requirement as per MORT&H 5th Rev. Bituminous Base & Wearing Courses requirement as per MORT&H 5th Rev.

Cement Concrete

Pavement (Wearing

surfaces)

Cement Concrete (Other than Wearing surfaces)

Sub Base, GSB Base Course, WBM Base Course,

Crushed WMM

Base Course, Crusher Run

Macadam

BASE COURSE/ BINDER COURSE

SURFACE COURSE/ WEARING CORSE

BM DBM SDBC BC

1

Deleterious

Materials and

Organic Impurities

Organic Matter IS-2386 (Part-2)

1.00% Max 1.00% Max 1.00% Max 1.00% Max Nil Nil Nil Nil Nil Nil

Sodium Sulphate IS-2386

(Part-2) 0.20% Max 0.20% Max 0.20% Max 0.20% Max NIl Nil NIl NIl NIl NIl

2 Cleanliness Grain size Analysis IS-2386

Part – 1 - - - -

Max 5%

Passing

75 µ sieve

Max 5%

Passing

75 µ sieve

Max 5% Passing

75 µ sieve

Max 5%

Passing

75 µ sieve

- -

3 Strength

Los Angeles Abrasion IS-2386

Part – 4

Not Specified

in MORT&H Max 40 % Max 40 % Max 40 % Max 40 % Max 35 % Max 35 % Max 30 % 30 % Max 50 % Max

Crushing value IS-2386

Part – 4 Max 45% Max 45% Max 45% Max 45% Max 45% Max 45% Max 30 % Max 30 % 30 % Max 30 % Max

Agg. Impact value IS-2386- 4) or

IS-5640 Max 40 % Max 30 % Max 30 % 30 % Max Max. 30% Max. 27 % Max. 27% Max. 24 % 30 % Max 45 % Max

10 % Fines Value IS-2386 Part -

IV or BS 812-

111 50 Kn. -Min. - - - - - - - - 50 kN

4 Days Soaked CBR IS-2720

(Part-16) Min 30% - - - - - - - - -

4 Durability Aggregate Soundness

test* *(If W.A. greater

than 2%)

IS-2386 Part –V

- - - - Max 12%

( Na₂SO₄)

Max 12%

( Na₂SO₄)

Max 12%

( Na₂SO₄)

Max 12%

( Na₂SO₄) - -

- - - - Max 18%

( MgSO₄)

Max 18%

( MgSO₄)

Max 18%

( MgSO₄)

Max 18%

( MgSO₄) - -

5 Shape

Flakiness Index IS-2386

Part –I Not

Mentioned in

MORT&H

35 % Max.

(Combined FI + EI)

35 % Max.

(Combined FI

+ EI)

35 % Max.

(Combined

FI + EI)

35 % Max.

(Combined

FI + EI)

35 % Max.

(Combined

FI + EI)

30 % Max.

(Combined

FI + EI)

30 % Max.

(Combined

FI + EI)

35 % Max.

(Combined

FI + EI)

40 % Max.

(Combined

FI + EI) Elongation Index IS-2386 Part –I

Angularity Index IS-2386

Part – 1 0 to 11 0 to 11 0 to 11 0 to 11 0 to 11 0 to 11 0 to 11 0 to 11 0 to 11

6 Liquid Limit Determination of

Liquid Limit and

Plasticity Index

IS-2720

(Part-5)

25% Max NA NA 25% Max - - - - -

7 Plasticity Index 6% Max 6% Max 6% Max 6% Max Non Plastic Non Plastic Non Plastic Non Plastic - -

8 Water Absorption Water Absorption IS-2386 Part

– 3 2 % Max. 2 % Max. 2 % Max. 2 % Max. 2 % Max. 2 % Max. 2 % Max. 2 % Max. 2 % Max. 2 % Max.

9 Specific Gravity Specific Gravity IS-2386

Part - 3 N.A. 2.6 to 2.9 2.6 to 2.9 2.6 to 2.9 2.6 to 2.9 2.6 to 2.9 2.6 to 2.9 2.6 to 2.9 2.6 to 2.9 2.6 to 2.9

10 Bitumen Adhesion Strippting Value IS-6241 NA NA NA NA Min. retained

coating 95%

Min. retained

coating 95%

Min. retained

coating 95%

Min.

retained

coating

95%

- -

11 Water Sensitivity Retained Tensile

Strength

AASHTO

283 - - - - Min. 80% Min. 80% Min. 80% Min 80% - -

12 Aggregate Softness Stone Polishing

Value

BS :

812-114 - - - - - - Min 55 Min 55 - -



SECTION-A

TESTS ON AGGREGATES

Sr. No. Name of Test Relevant Standard

1 Shape test (Flakiness Index + Elongation Index) IS:2386 PART-1

2 Aggregate Impact Test IS:2386 PART- 4

3 Aggregate Crushing Test IS:2386 PART- 4

4 Aggregate Los Angeles Abrasion Test IS:2386 PART-5

5 Specific Gravity and Water Absorption Test IS: 2386 PART-3

6 Gradation and Blending of Aggregate IS 383-2016



Experiment 1 Date: ___/___/_____

SHAPE TEST (IS: 2386 PART - 1)

OBJECTIVE:

• To determine the value of Flakiness and Elongation Index of Coarse aggregates and

Combined Index (CI) = FI+EI

• The flakiness index of an aggregate is the percentage by weight of particles in it

whose least dimension (thickness) is less than three-fifths times of their mean

dimension. The test is not applicable to sizes smaller than 6.3 mm.

• The elongation index of an aggregate is the percentage by weight of particles whose

greatest dimension (length) is greater than nine-fifths times of their mean

dimension. The test is not applicable to sizes smaller than 6.3 mm.

APPARATUS:

• Thickness gauge for Flakiness Index as shown in Figure-1

• Length gauge for Elongation Index as shown in Figure-2

• Balance of capacity not less than 500 g with an accuracy of 0.1 % of the weight of the test

sample

• IS Sieve as shown in Table 1

Figure 1 Thickness Gauge



Figure 2 Length Gauge

TEST SAMPLE:

• A quantity of aggregate shall be taken sufficient to provide the minimum number of 200

pieces of any fraction to be tested.

TEST PROCEDURE:

• The sample shall be sieved with the sieves specified the Table-1

• Each fraction shall be gauged in turn for thickness on thickness gauge as shown in Figure

1.

• The thickness of slot for a specific sample size is worked out as follows:

o For sample passing through 40 mm sieve and getting retained on 25 mm sieve the

average size is (40+25) / 2 = 32.5 mm

o Thickness of slot = 0.6 x 32.5 = 19.5 mm

o Same calculation applies to all sample sizes

• The total amount passing the gauge shall be weighed to an accuracy of at least 0.1% of the

weight of the test.

• The flakiness index is the total weight of the material passing the various thickness gauges,

expressed as a percentage of the total weight of the sample gauged.

• After carrying out the flakiness index test, the flaky material shall be removed from the

sample and the remaining portion (Non-Flaky Material) will be used as a sample for

carrying out elongation index.

• Each fraction shall be gauged individually for length on a length gauge as shown in Figure

2.

• The length of slot for a specific sample size is worked out as follows:



o For sample passing through 40 mm sieve and getting retained on 25 mm sieve the

average size is (40+25) / 2 = 32.5 mm

o Thickness of slot = 1.8 x 32.5 = 58.5 mm

o Same calculation applies to all sample sizes

• The total amount retained on the gauge shall be weighed to an accuracy of at least 0.1% of the

weight of the test.

• The elongation index is the total weight of the material retained on the various length gauges,

expressed as a percentage of the total weight of the non-flaky sample gauged.

• Indices so worked out shall be numerically added to give combined flakiness and elongation

index.

• Flakiness index and elongation index can also be determined and reported separately with out

numerically adding them, in this case the sample is quantity of aggregate, sufficient to provide

a minimum number of 200 pieces to be gauged for thickness as well as length on thickness

gauge and length gauge respectively. Rest of the procedure remains same as mentioned in

previous points.

OBSERVATION TABLE:

Table 1: Observation Table for Flakiness and Elongation Index

Sr.

No.

FLAKINESS INDEX ELONGATION INDEX

Passing

through

IS sieve

(mm)

Retained

on IS

sieve

(mm)

Weight of

200 Nos.

Aggregate

(gms)

Weight of

aggregate (Flaky)

passing the

thickness Gauge

(gms)

Weight of Non-

Flaky

Aggregate

taken as sample

(gms)

Weight of the

aggregate

(Elongated) retained

on the length Gauge

(gms)

A B C D E = C – D F

1. 63 50 - -

2. 50 40

3. 40 25

4. 31.5 25 - -

5. 25 20

6. 20 16

7. 16 12.5

8. 12.5 10

9. 10 6.3

W = w = W1 = w1 =

FI = (w / W) x 100 = EI = (w1 / W1) x 100 =

Combined index (CI) = Flakiness Index (FI) + Elongation Index (EI) = % + % = %



RESULT:

CONCLUSION:

EXERCISE:

1) Draw neat sketch of Thickness Gauge and Length Gauge showing all the dimensions.



2) Slot dimension for flakiness index and elongation index for aggregates passing through 25mm

and retained on 20 mm sieves would be respectively……………………………… (GATE

question)

(a) 13.5 and 40.5 mm(b) 40.5 and 13.5 mm(c )10.8 and 32.4 mm (d ) 27.0 and 81.0 mm

Show calculation:

3) Allowable maximum Combined Index (FI+EI) value for

Granular sub-base (GSB) = . . . . . . . . . . .%

Water bound macadam (WBM) = . . . . . . . . .%

Dense Bituminous macadam (DBM) = . . . . . . . . . .% and

Bituminous concrete (BC) = . . . . . . . . . .%

4) The flakiness and elongation index tests are not applicable for aggregate sizes smaller

than…………

(a) 6.3 mm (b) 4.75 mm (c) 2.36 mm (d) 10 mm

Faculty’s Signature




AGGREGATE IMPACT VALUE TEST (IS: 2386 PART - 4)

OBJECTIVE:

• To determine the aggregate impact value of coarse aggregate

• The aggregate impact value gives a relative measure of the resistance of an

aggregate to sudden shock or impact, which in some aggregates differs from its

resistance to a slow compressive load.

APPARATUS:

• An impact testing machine as shown in figure and complying with the following:

o Total weight of machine not more than 60 kg nor less than 45 kg

o Machine shall have metal base weighing 22 to 30 kg with plane lower surface of

minimum 30 cm diameter.

o A cylindrical steel cup of internal dimensions 102 mm diameter, 50 mm depth and

6.3 mm minimum thickness

o A metal tup or hammer weighing 13.5 to 14 kg, the lower end shall be cylindrical

in shape, 100 mm diameter and 5 cm long, with a 2 mm chamfered lower edge.

o Means for raising and adjusting the height of hammer to 380 ± 5 mm to allow it to

fall freely on to the test sample in cup.

o Means for supporting the hammer whilst fastening or removing the cup.

• Sieves of sizes 12.5 mm, 10.0 mm and 2.36 mm.

• A cylindrical measure of internal dimensions 75 mm diameter and 50 mm diameter.

• Tamping rod of circular cross section 10 mm in diameter and 230 mm long, rounded at

one end.

• Balance of capacity not less than 500 g, and accurate to 0.1 g

• A ventilated oven thermostatically controlled to maintain a temperature of 100 to 110oC.

Cylindrical

Measure

Tamping

Rod



TEST SAMPLE:

• The test sample shall consist of aggregate the whole of which passes a 12.5 mm IS Sieve

and is retained on a 10 mm IS Sieve.

• The aggregate comprising the test sample shall be dried in an oven for a period of four

hours at a temperature of 100 to 110°C and cooled.

• The measure shall be filled about one-third full with the aggregate and tamped with 25

strokes of the rounded end of the tamping rod further similar quantity of aggregate shall be

added and a further tamping of 25 strokes given. The measure shall finally be filled to

overflowing, tamped 25 times and the surplus aggregate struck off, using the tamping rod

as a straight-edge.

• The net weight of aggregate in the measure shall be determined to the nearest gram (Weight

A) and this weight of aggregate shall be used for the duplicate test on the same material.

TEST PROCEDURE:

• The impact machine shall rest without wedging or packing upon the level plate, block or

floor, so that it is rigid and the hammer guide columns are vertical.

• The cup shall be fixed firmly in position on the base of the machine and the whole of the

test sample is placed in it and compacted by a single tamping of 25 strokes of the tamping

rod

• The hammer shall be raised until its lower face is 380 mm above the upper surface of the

aggregate in the cup, and allowed to fall freely on to the aggregate. The test sample shall

be subjected to a total of 15 such blows each being delivered at an interval of not less than

one second.

• The crushed aggregate shall then be removed from the cup and the whole of it sieved on

the 2.36-mm IS Sieve until no further significant amount passes in one minute. The fraction

passing the sieve shall be weighed to an accuracy of 0.1 g (Weight B)

• The fraction retained on the sieve shall also be weighed (Weight C) and, if the total Weight

(B+C) is less than the initial weight (Weight A) by more than one gram, the result shall be

discarded, and a fresh test made. Two tests shall be made.



CALCULATION:

• The ratio of the weight of fines formed to the total sample weight in each test shall he

expressed as a percentage; the result being recorded to the first decimal place:

Aggregate impact value =𝐵

𝐴 𝑋 100

Where, B = Weight of fraction passing 2.36-mm IS Sieve,

A = Weight of oven-dried sample.

REPORTING OF RESULTS:

• The mean of the two results shall be reported to the nearest whole number as the aggregate

impact value of the tested material.

OBSERVATION TABLE:

Table 1: Observation Table for Aggregate Impact Value Test

Sr.

No. Description Test -1 Test-2

1. Original weight of the aggregate passing through 12.5 mm IS

sieve and retained on 10 mm IS sieve, A g

2. Weight of sample passes 2.36 mm IS sieve after test B g

3. Weight sample retain 2.36 mm IS sieve after test C g

4. D = B + C (If A – D > 1 g, then sample must be discarded)

5. Aggregate Impact Value (%) = 𝐵

𝐴 x 100

6. Avg. Aggregate Impact Value in %

RESULT:

CONCLUSION:



EXERCISE:

1) Draw a neat sketch Aggregate Impact test apparatus showing all the dimensions

2) The test sample shall be subjected to………..blows each being delivered at an interval of not

less than one second.

3) Aggregate passing from………..mm and retained on………..mm sieve is used as test sample.

4) The hammer weighing…………..kg is allowed to fall freely from a height of …………mm on

the test sample.

5) Allowable maximum Impact value for

Granular Sub-Base (GSB) =. . . . . . . . .%

Water Bound Macadam (WBM) = . . . . . . . . .%

Dense Bituminous Macadam (DBM) = . . . . . . . . . and

Bituminous Concrete (BC) = . . . . . . . . . %

6)The……………………of aggregate is checked by Aggregate Impact Value Test.





AGGREGATE CRUSHING VALUE TEST (IS: 2386 PART - 4)

OBJECTIVE:

• To determine the aggregate crushing value of coarse aggregate

• The aggregate impact value gives a relative measure of the resistance of an

aggregate to crushing under a gradually applied compressive load.

APPARATUS:

• A 15 cm diameter open-ended cylinder, with plunger and base plate, of the general form

and dimensions shown in figure.

• A straight metal tamping rod of circular cross-section 16 mm in diameter and 45 to 60 cm

long, rounded at one end.

• A balance of capacity 3 kg, readable and accurate to one gram.

• IS sieves of sizes 12.5 mm, 10 mm and 2.36 mm.

• A compression testing machine capable of applying load of 40 tonnes and which can be

operated to give a uniform rate of loading so that the maximum load is reached in 10

minutes.

• For measuring the sample, cylindrical metal measure of internal dimension diameter 11.5

cm and height 18 cm.

APPARATUS:

• A 15 cm diameter open-ended cylinder, with plunger and base plate, of the general form

and dimensions shown in figure.

• A straight metal tamping rod of circular cross-section 16 mm in diameter and 45 to 60 cm

long, rounded at one end.

• A balance of capacity 3 kg, readable and accurate to one gram.

• IS sieves of sizes 12.5 mm, 10 mm and 2.36 mm.

• A compression testing machine capable of applying load of 40 tonnes and which can be

operated to give a uniform rate of loading so that the maximum load is reached in 10

minutes.

• For measuring the sample, cylindrical metal measure of internal dimension diameter 11.5

cm and height 18 cm.



TEST SAMPLE:

• The material for the standard test shall consist of aggregate passing 12.5 mm IS sieve and

retained on a 10 mm IS sieve.

• The aggregate shall be tested in a surface-dry condition. If dried by heating, the period of

drying shall not exceed four hours, the temperature shall be 100 to 110oC and the aggregate

shall be cooled to room temperature before testing.

• The quantity of aggregate shall be such that the depth of material in the cylinder, after

tamping as mentioned below shall be 10 cm.

• The appropriate quantity may be found conveniently by filling the cylindrical measure in

three layers of approximately equal depth, each layer being tamped 25 times with rounded

end of tamping rod and levelled off, using the tamping as a straight edge.



• The weight of material comprising the test sample shall be determined (Weight A) and the

same weight of sample shall be taken for the repeat test.

TEST PROCEDURE:

• The cylinder of test apparatus is positioned on base plate and the test sample is added in

thirds; each third being subjected to 25 strokes from the tamping rod.

• The surface of the aggregate shall be carefully levelled, and the plunger inserted so that it

rests horizontally on this surface, care being taken to ensure that the plunger does not jam

in the cylinder.

• The apparatus, with the test sample and plunger in position, shall then be placed between

the platens of the testing machine and loaded at as uniform a rate as possible so that the

total load is reached in 10 minutes. The total load shall be 40 tonnes i.e, 400 kN. (4 tonnes

per minute)

• The load shall be released and the whole of the material removed from the cylinder and

sieved on 2.36 mm IS sieve. The fraction passing the sieve shall be weighed (Weight B).

• In all operations, care shall be taken to avoid loss of the fines. Two tests shall be made.

CALCULATION:

• The ratio of the weight of fines formed to the total sample weight in each test shall he

expressed as a percentage; the result being recorded to the first decimal place:

Aggregate crushing value =𝐵

𝐴 𝑋 100

Where, B = Weight of fraction passing 2.36-mm IS Sieve,

A = Weight of surface-dry sample.


• The mean of the two results shall be reported to the nearest whole number as the aggregate

crushing value of the tested material.



OBSERVATION TABLE:

Table 1: Observation Table for Aggregate Crushing Value Test

Sr.

No. Description Test -1 Test-2

1. Original weight of the aggregate passing through 12.5

mm IS sieve and retained on 10 mm IS sieve, A g

2. Weight of sample passing through 2.36 mm IS sieve after

test, B g

3. Weight of sample retained on 2.36 mm IS sieve after test,

C g

4. Aggregate Crushing Value (%) = 𝐵

𝐴 x 100

5. Avg. Aggregate Crushing Value in %

RESULT:

CONCLUSION:

EXERCISE:

1) What is the size of aggregate on which crushing test is performed?

2) What is the total load that is to be applied on aggregate during crushing test and at what rate the

load must be applied?



3) What type of load is applied on aggregate during crushing test?

(a) Sudden Load (b) Gradual Load

4) Allowable maximum crushing value for



Dense Bituminous Macadam (DBM) = . . . . . . . . .% and


5) Draw neat sketch of Aggregate Crushing Value Test apparatus showing all the dimensions.





SPECIFIC GRAVITY & WATER ABSORPTION TEST (IS: 2386 PART - 3)

OBJECTIVE:

• To determine specific gravity, apparent specific gravity and water absorption of

aggregates

NOTE:

• Three main methods are specified for use according to whether the size of the aggregate is

o Larger than 10 mm (Method I)

o Between 40 mm and 10 mm (Method I or II)

o Smaller than 10 mm (Method III)

METHOD I – AGGREGATE LARGER THAN 10 mm

APPARATUS:

• A balance of capacity not less than 3 kg, readable and accurate to 0.5 g and of such a type

and shape as to permit the basket containing the sample to be suspended from beam and

weighed in water.

• A well-ventilated oven, thermostatically controlled, to maintain a temperature of 100 to

110oC

• A wire basket of not more than 6.3 mm mesh or a perforated container of convenient size,

with wire hangers not thicker than 1 mm for suspending it from the balance.

• A stout watertight container in which the basket may be freely suspended.

• Two dry soft absorbent cloths each not less than 75 x 45 cm.

• A shallow tray of area not less than 650 cm2.

SAMPLE:

• A sample of not less than 2000 g of the aggregate shall be tested.

• Aggregates which have been artificially heated shall not normally be used; if such material

is used, the fact shall be stated in the report.

• Two tests shall be made, and it is recommended that the two samples should not be tested

concurrently.

TEST PROCEDURE:

• The sample is washed thoroughly to remove fines, drained and then placed in wire basket

and immersed in distilled water at a temperature between 22- 32º C and a cover of at least

5 cm of water above the top of basket.

• Immediately after immersion the entrapped air is removed from the sample by lifting the

basket containing it 25 mm above the base of the tank and allowing it to drop at the rate of



about one drop per second. The basket and aggregate should remain completely immersed

in water for a period of 24 hour ± ½ hour.

• The basket and the sample shall then be jolted and weighed in water at a temperature of 22

to 32oC. Weight is denoted as A1.

• The basket and the aggregate shall then be removed from the water and allowed to drain

for a few minutes, after which the aggregate shall be gently emptied from the basket on to

one of the dry clothes, and the empty basket shall be returned to water, jolted 25 times and

weighed in water, Weight A2.

• The aggregate placed on the dry cloth shall be surface dried with the cloth. It shall then be

spread out on the second cloth and exposed to atmosphere away from direct sunlight for

not less than 10 minutes. The aggregate shall then be weighed, Weight B.

• The aggregate shall then be placed in the oven in the shallow tray, at a temperature of 100

to 110°C and maintained at this temperature for 24 ± l/2 hours. It shall then be removed

from the oven, cooled in the airtight container and weighed, Weight C.

CALCULATION:

• Specific gravity, apparent specific gravity and water absorption shall be calculated as

follows:

o Specific gravity = 𝐶

𝐵−𝐴

o Apparent specific gravity = 𝐶

𝐶−𝐴

o Water absorption (percent of dry weight) = 100 (𝐵−𝐶)

𝐶

Where, A = Weight in g of the saturated aggregate in water, A1 – A2

B = Weight in g of the saturated surface-dry aggregate in air,

C = Weight in g of oven-dried aggregate in air.


• The individual and mean results shall be reported. The size of the aggregate tested shall be

stated, and whether it has been artificially heated

OBSERVATION TABLE:

Sr. No. Description Observation

1 Weight of basket + aggregate after 24-hour soaking, A1 g

2 Weight of empty basket in water, A2 g.

3 The weight of saturated aggregate in water, A = A1 -A2

4 Weight of saturated surface dry aggregate in air, B g

5 Weight of 24-hour oven dried aggregate, C g

6 Specific gravity = C / B - A

7 Apparent specific gravity =C / (C –A)

8 Water absorption = [100 (B-C) /C]



Result:

Specific Gravity =

Apparent Specific Gravity =

Water Absorption =

METHOD II – AGGREGATE BETWEEN 40 mm and 10 mm

APPARATUS:


and shape as to permit the weighing of the vessel containing the aggregate and water.


110oC

• A wide-mouthed glass vessel such as a jar of about 1.5 litres capacity with. a flat ground

lip and a plane ground disc of plate glass to cover it, giving a virtually watertight fit.

• Two dry soft absorbent cloths each not less than 75 x 45 cm.

• A shallow tray of area not less than 325 cm2.

• An airtight container large enough to take the sample.

SAMPLE:

• A sample of about 1000 g of the aggregate shall be tested.




concurrently.

TEST PROCEDURE:

• The sample shall be screened on a 10 mm IS sieve, thoroughly washed to remove fine

particles of dust, and immersed in distilled water in the glass vessel; it shall remain

immersed at a temperature of 22 to 32oC for 24 ± ½ hours.

• Soon after immersion and again at the end of the soaking period, air entrapped in or bubbles

on the surface of the aggregate shall be removed by gentle agitation. This may be achieved

by rapid clockwise and anti-clockwise rotation of the vessel between the operator’s hands.

• The vessel shall be overfilled by adding distilled water and the plane ground glass slid over

the mouth to ensure that no air is entrapped in the vessel. The vessel shall be dried on the

outside and weighed, Weight A.

• The vessel shall be emptied, and the aggregate allowed to drain. Refill the vessel with

distilled water. Slide the glass disc in position as before. The vessel shall be dried on the

outside and weighed Weight B.



• The aggregate shall be placed on a dry cloth and gently surface dried with the cloth, it shall

then be spread out on the second cloth and left exposed to the atmosphere away from direct

sunlight for at least 10 minutes. The aggregate shall then be weighed, Weight C.

• The aggregate shall then be placed in the oven in the shallow tray, at a temperature of 100

to 110°C and maintained at this temperature for 24 ± l/2 hours. It shall then be removed

from the oven, cooled in the airtight container and weighed, Weight D.

CALCULATION:


follows:

o Specific gravity = 𝐷

𝐶−(𝐴−𝐵)

o Apparent specific gravity = 𝐷

𝐷−(𝐴−𝐵)

o Water absorption (percent of dry weight) = 100 (𝐶−𝐷)

𝐷

Where, A = Weight in g vessel containing sample and filled with distilled water,

B = Weight in g of vessel filled with distilled water only,

C = Weight in g of saturated surface-dry sample, and

D = weight in g of oven dry sample



stated, and whether it has been artificially heated

OBSERVATION TABLE:


1 Weight of vessel containing sample and filled with distilled

water, A g

2 Weight of vessel filled with distilled water, B g

3 Weight of saturated surface-dry sample, C g

4 Weight of oven dry sample, D g

5 Specific gravity = [D / C – (A - B)]

6 Apparent specific gravity = [D / D – (A - B)]

7 Water absorption = [100 (C - D) /D]

Result:

Specific Gravity =


Water Absorption =



METHOD III – AGGREGATE SMALLER THAN 10 mm

APPARATUS:


and shape as to permit the weighing of the vessel containing the aggregate and water.


110oC

• Any form of vessel capable of holding 0.5 to 1 kg of material up to 10 mm in size and

capable of being filled with water to a constant volume with an accuracy of ± 0.5 ml. Either

of the two following vessels is suitable:

o Pycnometer

o A wide-mouthed glass vessel such as a jar of about 1.25 litres capacity with. a flat

ground lip and a plane ground disc of plate glass to cover it, giving a virtually

watertight fit.

• A means of supplying a current of warm air, such as hair dryer.

• A tray of area not less than 325 cm2.

• An airtight container enough to take the sample.

• Filter papers and funnel.

SAMPLE:

• A sample of about 1000 g for 10 mm to 4.75 mm aggregate or 500 g if finer than 4.75 mm

shall be tested.




concurrently.

TEST PROCEDURE:

USING A PYCNOMETER

• The sample shall be placed in the tray and covered with distilled water at a temperature of

22 to 32oC.

• Soon after immersion, air entrapped in or bubbles on the surface of the aggregate shall be

removed by gentle agitation with a rod. The sample shall remain immersed for 24 ± ½

hours.

• The water shall then be carefully drained from the sample, by decantation through a filter

paper, any material retained being returned to the sample.

• The aggregate including any solid matter retained on the filter paper shall be exposed to a

gentle current of warm air to evaporate surface moisture and shall be stirred at frequent

intervals to ensure uniform drying until no free surface moisture can be seen and the

material just attains a ‘ free-running ’ condition.

• The saturated and surface-dry sample shall be weighed, Weight A.



• The aggregate shall then be placed in the pycnometer which shall be filled with distilled

water. Any trapped air must be removed.

• The pycnometer shall be topped up with distilled water and it shall be dried on the outside

and weighed, Weight B

• The pycnometer shall be emptied into the tray, and the aggregate is transferred. Refill the

pycnometer with distilled water to the same level as before, dried on the outside and

weighed, Weight C.

• The water shall then be drained from the sample by decantation through filter paper and

any material retained must returned to the sample.

• The sample shall be placed in the oven in the tray at a temperature of 100 to 110oC for 24

± ½ hours. It shall be cooled in an air-tight container and weighed, Weight D.

USING A WIDE-MOUTHED GLASS JAR

• The procedure shall be the same except that in filling the jar with water it shall be filled

just to overflowing and the glass plate slid over it to exclude any air bubbles.

CALCULATION:


follows:

o Specific gravity = 𝐷

𝐴−(𝐵−𝐶)

o Apparent specific gravity = 𝐷

𝐷−(𝐵−𝐶)

o Water absorption (percent of dry weight) = 100 (𝐴−𝐷)

𝐷

Where, A = Weight in g of saturated surface dry sample,

B = Weight in g of pycnometer or glass jar containing sample and filled

with distilled water,

C = Weight in g of pycnometer or glass jar filled with distilled water only,

and

D = weight in g of oven dry sample



stated.



OBSERVATION TABLE:


1 Weight of saturated surface dry sample, A g

2 Weight of pycnometer or glass jar containing sample and

filled with distilled water, B g

3 Weight of pycnometer or glass jar filled with distilled water

only, C g

4 Weight of oven dry sample, D g

5 Specific gravity = [D / A – (B - C)]

6 Apparent specific gravity = [D / D – (B - C)]

7 Water absorption = [100 (A - D) /D]

Result:

Specific Gravity =


Water Absorption =





AGGREGATE ABRASION VALUE TEST (IS: 2386 PART - 4)

OBJECTIVE:

• To determine the aggregate abrasion value.

APPARATUS:

• The Los Angeles abrasion testing machine having following specifications:

o The machine shall consist of a hollow steel cylinder, closed at both ends, having an

inside diameter of 700 mm and an inside length of 500 mm.

o An opening in the cylinder shall be provided for the introduction of the test sample.

o The opening shall be closed dust-tight with a removable cover bolted in place.

o A removable steel shelf, projecting radially 88 mm into the cylinder and extending

its full length, shall be mounted along one element of the interior surface of the

cylinder.

• IS sieve of 1.7 mm size.

• The abrasive charge shall consist of cast iron spheres or steel spheres approximately 48

mm in diameter and each weighing between 390 and 445 g.

SAMPLE:

• The test sample shall consist of clean aggregate which has been dried in an oven at 105 to

110oC and shall conform to one of the gradings as shown in table below.

Gra

din

g

Weight in grams of test sample for different gradings (Sieve size in mm) N

o. of

sph

ere

Total

Weight of

Charge

in grams 80-63 63-50 50-40 40-25 25-20 20-12.5 12.5-10 10-6.3 6.3-4.75 4.75-2.36

A --- --- --- 1250 1250 1250 1250 --- --- --- 12 5000±25

В --- --- --- --- --- 2500 2500 --- --- --- 11 4584±25

С --- --- --- --- --- --- --- 2500 2500 --- 8 3330±20

D --- --- --- --- --- --- --- --- --- 5000 6 2500+15

E 2500* 2500* 5000* --- --- --- --- --- --- --- 12 5000+25

F --- --- 5000* 5000* --- --- --- --- --- --- 12 5000±25

G --- --- --- 5000* 5000* --- --- --- --- --- 12 5000+25

* Tolerance of ±2 percent is permitted



TEST PROCEDURE:

• The test sample and the abrasive charge shall be placed in the Los Angeles abrasion testing

machine and the machine rotated at a speed of 20 to 33 rev/min.

• For Grading A, B, C and D, the machine shall be rotated for 500 revolutions

• For Grading E, F and G, it shall be rotated for 1000 revolutions.

• The machine shall be so driven and so counter-balanced as to maintain a substantially

uniform peripheral speed. If an angle is used as the shelf, the machine shall be rotated in

such a direction that the charge is caught on the outside surface of the angle.

• At the completion of the test, the material shall be discharged from the machine and a

preliminary separation of the sample made on a sieve coarser than the l.70-mm IS Sieve.

The finer portion shall then be sieved on a 1.70-mm IS Sieve.

• The material coarser than the 1.70-mm IS Sieve shall be washed dried in an oven at 105 to

110°C to a substantially constant weight, and accurately weighed to the nearest gram,

Weight WB



CALCULATION:

• Aggregate abrasion value shall be calculated as follows:

o Aggregate abrasion value =𝑊𝐴−𝑊𝐵

𝑊𝐴 𝑋 100

Where, WA = Original weight of the test sample

WB = Final weight of the test sample (Material coarser than 1.7

mm)


• The Difference between the original weight and the final weight of the test sample shall be

expressed as a percentage of the original weight of the test sample. This value shall be

reported as the percentage of wear.

OBSERVATION TABLE:

Sr. No. Description Test-1 Test-2

1 Original weight of the test sample, WA g

2 Final weight of the test sample (Material coarser than 1.7

mm), WB g

3 Abrasion Value in % = [ (WA - WB) / WA ] x 100

4 Average Abrasion Value

Result:

Conclusion:



Exercise:

1) Allowable maximum crushing value for



Dense Bituminous Macadam (DBM) = . . . . . . . . .%


Cement Concrete Pavement (Wearing Pavement) = . . . . . . . . . . %

2) The ………………….. property of aggregate is checked by Abrasion test.

3) For grading A, B, C & D the machine shall be rotated for ……………… revolutions and for E,

F & G the machine shall be rotated for ………………revolutions.





GRADATION & BLENDING OF AGGREGATES (IS: 383 - 2016)

OBJECTIVE:

• To determine particle size of aggregates and to mix aggregates of different sizes in

appropriate proportions to meet the requirements of given gradation for any specific

construction work.

APPARATUS:

• The balance or scale shall be such that it is readable and accurate to 0.1 percent of the

weight of the test sample.

• All the sieves of sizes which are being used for concrete construction as well as pavement

construction

o Square hole type sieves of sizes 80 mm, 63 mm, 50 mm, 40 mm, 25 mm, 20 mm,

16 mm, 12.5 mm, 10.0 mm, 6.3 mm, 4.75 mm.

o Fine mesh type sieves of sizes 3.35 mm, 2.36 mm, 1.18 mm, 600 micron, 300

micron, 150 micron, 75 micron.

• The balance or scale shall be such that it is readable and accurate to 0.1 % of the weight of

the test sample.

SAMPLE:

• The weight of the sample shall not be less than the weight given in the following table. The

sample for sieving shall be prepared from the larger sample either by quartering or by

means of sample divider. The sample for sieving is also shown in following table.

Aggregate

size in mm

Minimum Weight of sample

dispatched for testing in kg

Minimum weight of sample to

be taken for sieving in kg

63 100 50

50 100 35

40 50 15

25 50 5

20 25 2

16 25 2

12.5 12 1

10.0 6 0.5

6.3 3 0.2

4.75 -- 0.2

2.36 -- 0.1



TEST PROCEDURE:

• The sample shall be brought to an air-dry condition before weighing and sieving. This may

be achieved either by drying at room temperature or by heating at a temperature of 100o to

110o C.

• The air-dry sample shall be weighed and sieved successively on the appropriate sieves

starting with the largest. Care shall be taken to ensure that the sieves are clean before use.

• Each sieve shall be shaken separately over a clean tray until not more than a trace passes,

but in any case, for a period of not less than two minutes.

• The shaking shall be done with a varied motion, backwards and forwards, left to right,

circular clockwise and anti-clockwise, and with frequent jarring, so that the material is kept

moving over the sieve surface in frequently changing directions.

• Material shall not be forced through the sieve by hand pressure, but on sieves coarser than

20 mm, placing of particles is permitted.

• Lumps of fine material, if present, may be broken by gentle pressure with fingers against

the side of the sieve. Light brushing with a soft brush on the underside of the sieve may be

used to clear the sieve openings.

• Light brushing with a fine camel hairbrush may be used on the 150-micron and 75-micron

IS Sieves to prevent aggregation of powder and blinding of apertures. Stiff or worn out

brushes shall not be used for this purpose and pressure shall not be applied to the surface

of the sieve to force particles through the mesh.

• On completion of sieving, the material retained on each sieve, together with any material

cleaned from the mesh, shall be weighed.

WHAT IS MAXIMUM SIZE OF AGGREGATE (MSA)?

• The smallest sieve through which 100 percent of the aggregate sample particles pass.

WHAT IS NOMINAL MAXIMUM SIZE OF AGGREGATE (NMSA)?

• The largest sieve that retains some of the aggregate particles but generally not more than

10 percent by weight.



The grading of coarse aggregates and fine aggregates when determined shall be within the

limits as shown in following tables (AS PER IS: 383-2016)

Coarse Aggregates

Fine Aggregates

OBSERVATION TABLE:

Sieve Analysis for 20 mm size aggregate

Sample Weight: ……………… g

IS Sieve Size in

mm

Weight Retain

(g)

% Weight

Retain

Cumulative %

Weight Retain

Cumulative %

Weight Passing

IS Sieve

size in

mm

% Passing of single sized aggregate of

Nominal Size

% Passing for graded aggregate

of Nominal size

63 mm 40 mm 20 mm 16 mm 12.5 mm 10 mm 40 mm 20 mm 16 mm 12.5 mm

80 100 - - - - - 100 - - -

63 85-100 100 - - - - - - - -

40 0-30 85-100 100 - - - 90-100 100 - -

20 0-5 0-20 85-100 100 - - 30-70 90-100 100 100

16 - - - 85-100 100 - - - 90-100 -

12.5 - - - - 85-100 100 - - - 90-100

10 0-5 0-5 0-20 0-30 0-45 85-100 10-35 25-55 30-70 40-85

4.75 - - 0-5 0-5 0-10 0-20 0-5 0-10 0-10 0-10

2.36 - - - - 0-5 - - - -

IS Sieve

size in

mm

Percentage Passing

Grading

Zone I

Grading

Zone II

Grading

Zone III

Grading

Zone IV

10 100 100 100 100

4.75 90-100 90-100 90-100 95-100

2.36 60-95 75-100 85-100 95-100

1.18 30-70 55-90 75-100 90-100

0.6 15-34 35-59 60-79 80-100

0.03 5-20 8-30 12-40 15-50

0.15 0-10 0-10 0-10 0-15



Sieve Analysis for 10 mm size aggregate

Sample Weight: ……………… g

IS Sieve Size in

mm

Weight Retain

(g)

% Weight

Retain

Cumulative %

Weight Retain

Cumulative %

Weight Passing

NOTE: In all Indian Standard (IS) codes, Indian Roads Congress (IRC) Guidelines, Ministry of Road Transport & Highways

(MoRT&H) Specification Book, aggregate gradation is represented by PERCENTAGE WEIGHT PASSING which is same as

CUMULATIVE PERCENTAGE WEIGHT PASSING.

Mix both the above tested aggregates in such a manner to produce a mixture which satisfies

the grading criteria given in the last column of following table.

IS Sieve Size

in mm

Cumulative

% Weight

Passing of

Try-1 Try-2 Try-3

Range of

Grading for

Mix

Aggregates 20mm 10mm

……% of

Wt. Passing

of 20mm

+

……% of

Wt. Passing

of 10mm

……% of

Wt. Passing

of 20mm

+

……% of

Wt. Passing

of 10mm

……% of

Wt. Passing

of 20mm

+

……% of

Wt. Passing

of 10mm

40 100

20 90-100

10 25-55

4.75 0-10

The process carried out in the above table is known as BLENDING of aggregates i.e., Mixing

of different sizes of aggregates to obtained DESIRED GRADATION

What is DESIRED GRADATION?

• The answer to his question will vary depending upon the material, its desired

characteristics, loading, environmental, structural and mix property inputs.

• It might be reasonable to believe that the best gradation is one that produces the maximum

density.

• This would involve a particle arrangement where smaller particles are packed between the

larger particles, which reduces the void space between particles. This creates more particle-

to-particle contact, which in HMA would increase stability and reduce water infiltration.

• However, some minimum amount of void space is necessary to:

o Provide adequate volume for the binder (asphalt binder) to occupy.



o Promote rapid drainage and resistance to frost action for base and subbase courses.

• Therefore, although it may not be the “best” aggregate gradation, a maximum density

gradation does provide a common reference.

• A widely used equation to describe a maximum density gradation was developed by Fuller

and Thompson in 1907. Their basic equation is:

P = (d/D)n

Where, P = % Finer than the sieve

d = aggregate size being considered

D = Maximum aggregate size to be used

n = parameter which for adjusting fineness or coarseness (for

maximum particle density n ≈ 0.5 according to Fuller and Thompson

and n ≈ 0.45 according to FHWA)

Calculations for a 0.45 Power Gradation Curve Using 19.0-mm Maximum Aggregate Size

Particle Size (mm) % Passing

19.0 P = (19/19)0.45 = 1.000 (100.0%)

12.5 P = (12.5/19)0.45 = 0.828 (82.8%)

9.5 P = (9.5/19)0.45 = 0.732 (73.2%)

2.36 P = (2.36/19)0.45 = 0.391 (39.1%)

0.300 P = (0.300/19)0.45 = 0.155 (15.50%)

0.075 P = (0.075/19)0.45 = 0.083 (8.3%)

Which are the different types of GRADATION?

1) Dense or Well Graded

• Refers to a gradation for maximum density. The mix is relatively impermeable. The most

common bituminous mix design in the US tend to use dense graded aggregate.

https://www.pavementinteractive.org/reference-desk/design/design-parameters/frost-action/



2) Gap Graded

• Refers to a gradation that contains only a small percentage of aggregate particles in the

mid-size range. HMA gap graded mixes can be prone to segregation during placement. The

mix design goal is to create stone-on-stone contact within the mixture. Since aggregates do

not deform as much as asphalt binder under load, this stone-on-stone contact greatly

reduces rutting.

3) Open Graded

• Refers to a gradation that contains only a small percentage of aggregate particles in the

small range. This results in more air voids because there are not enough small particles to

fill in the voids between the larger particles. This mix is designed to be water permeable.

The above discussed gradation types are prepared by mixing say two, three or four

different sizes of aggregate in appropriate proportion and this proportion can be

determined by using Iterative Method, Graphical Method and by using Microsoft

Excel.



EXERCISE:

1) The desired gradation and sieve analysis results of two different sizes of aggregates are given

in the table below. Determine the percentage proportion in which the two aggregates must be

mixed/blended to obtain the desired gradation.

Sieve size 12.5

mm

10.0

mm

4.75

mm

2.36

mm 600 µ 300 µ 150 µ 75 µ

Desired

Gradation 80-100 70-90 50-70 30-50 18-29 13-23 8-16 4-10

% passing

Aggregate A 100 60 30 10 2 0 0 0

% passing

Aggregate B 100 100 100 85 52.5 42.5 30 15

Mid value- P 90 80 60 40 23.5 18 12 7

The proportion of aggregates A and B shall be mixed in such a manner that the mixed so formed

passes 80-100 % (90% most ideal condition) when sieved through 12.5 mm sieve, passes 70-90%

(80% most ideal condition) when sieved through 10.0 mm sieve ……. and simultaneously for all

specified sieves.

SOLUTION: For iterative method following formula is used for blending of two aggregates

P = aA + bB

Where, P = Mid value of specified range of desired gradation for a sieve

a = proportion of Aggregate A in the mixture (in decimal or percentage)

A = percentage passing of Aggregate A for a sieve

b = proportion of Aggregate B in the mixture (in decimal or percentage)

B = percentage passing of Aggregate B for a sieve

NOTE: a + b = 1 - - -> b = 1 – a or a = 1 - b

Now the task is to determine a and b. So, develop a formula for a or b from the above-mentioned

equation.



or

Determine value of b for 2.36 mm sieve

b = (…… – .…..) / (.….. – .…..) = .….. / .….. = ………. (which means ……% of Aggregate B)

⸫ a = 1 – b = 1 – …… = 0.60 (which means …....% of Aggregate A)

So, now multiply all the percentage passing values of Aggregate A by ……, multiply all the

percentage passing values of Aggregate B by ……. and add both the results for each sieve. Check

the obtained values with the range of desired gradation and mid-value.

Fill answers in table below:

Sieve size 12.5

mm

10.0

mm

4.75

mm

2.36

mm 600 µ 300 µ 150 µ 75 µ

Desired

Gradation 80-100 70-90 50-70 30-50 18-29 13-23 8-16 4-10

% passing

Aggregate A

% passing

Aggregate B

Total

Mid value, P 90 80 60 40 23.5 18 12 7

Remarks

Keeping in view the remarks in above table further adjust the proportions of Aggregate A and B

Adjusted proportion of Aggregate A: ……….

Adjusted proportion of Aggregate B: ……….


percentage passing values of Aggregate B by ……. and add both the results for each sieve. Check

the obtained values with the range of desired gradation and mid-value.

P = aA + bB

⸫ aA + bB = P

⸫ aA + (1 – a) B = P

⸫ aA + B – aB = P

⸫ a (A – B) + B = P

⸫ a = (P - B) / (A - B)

P = aA + bB

⸫ aA + bB = P

⸫ (1 – b) A + bB = P

⸫ A – Ab + bB = P

⸫ A + b ( B – A) = P

⸫ b = (P - A) / (B - A)




Sieve size 12.5

mm

10.0

mm

4.75

mm

2.36

mm 600 µ 300 µ 150 µ 75 µ

Desired

Gradation 80-100 70-90 50-70 30-50 18-29 13-23 8-16 4-10

% passing

Aggregate A

% passing

Aggregate B

Total

Mid value, P 90 80 60 40 23.5 18 12 7

Remarks

RESULT:

2) For the same data as mentioned in exercise 1, find the proportions of Aggregate A and B by

using graphical method.

SOLUTION:

• Draw a box of size 10 cm x 10 cm on graph paper with two X-Axes (Horizontal Sides -

Top & Bottom) and two Y-Axes (Vertical Sides - Left & Right).

• Mark points 0 to 100 % at an interval of 10 % on bottom X-Axis and name the axis as %

Proportion of Aggregate A.

• Mark points 100 to 0 % at an interval of 10 % on top X-Axis and name the axis as %

Proportion of Aggregate B.

• Mark points 0 to 100 % at an interval of 10 % on Left and Right Y-Axis; name both the

axis as % Passing of Aggregate B and % Passing of Aggregate A respectively.

• For each sieve size join the points lying on Left and Right Y-Axis with a line segment.

o For e.g, % Passing of Aggregate A and B from 10 mm sieve is 60 and 100

respectively. Now, draw a line segment with its left end point on 100% on Left Y-

Axis and right end point on 60% on Right Y-Axis.

o Carry out the same procedure for all sieve sizes and mention sieve size above all

line segments.

o For 12.5 mm sieve the line segment will coincide with the top X-Axis of the graph.

• Now, line segments for each sieve size are drawn.



• For each sieve size mark/plot the points as the specification (desired gradation range) on

the line segments drawn as discussed in previously.

o For e.g., for 10 mm sieve the desired range of gradation is 70 to 90 %

o Now taking Y-Axis (Left or Right) as reference, mark two points 70 % and 90 %

on the line segment for 10 mm sieve.

o Carry out the same procedure for all sieve sizes.

• Now draw two vertical line segments touching the top and bottom X-Axis; these two

vertical lines drawn must fulfill following conditions:

o Both lines must pass through at least one or two points (plotted as discussed in

previous step).

o No point must be in between these two lines

o The number of points on the outer sides of these two lines must be more-or-less

equal.

• Now draw a center line in between the two vertical lines.

• The point at which the center line touches top and bottom X-Axis will be % Proportion of

Aggregate B and A respectively.



3) The desired gradation and sieve analysis results of three different sizes of aggregates are given

in the table below. Determine the percentage proportion in which the three aggregates must be

mixed/blended to obtain the desired gradation.

Sieve size

(mm) 12.5 9.5 4.75 2.36 1.18 0.600 0.300 0.150 0.075

Desired

Gradation 100 70-90 45-65 30-60 25-50 19-36 8-25 4-12 3-6

% passing

Aggregate A 100 62 8 2 0 0 0 0 0

% passing

Aggregate B 100 100 100 91 73 51 24 4 0

% passing

Aggregate C 100 100 78 52 36 29 24 20 18

Mid value- P 100 80 55 45 37.5 27.5 16.5 8 4.5

The proportion of aggregates A, B and C shall be mixed in such a manner that the mixed so formed

passes 100% when sieved through 12.5 mm, 70-90 % (80% most ideal condition) when sieved

through 9.5 mm sieve, passes 45-65 % (55% most ideal condition) when sieved through 4.75 mm

sieve ……. and simultaneously for all specified sieves.

SOLUTION: For iterative method following formula is used for blending of three aggregates

P = aA + bB + cC

Where, P = Mid value of specified range of desired gradation for a sieve

a = proportion of Aggregate A in the mixture (in decimal or percentage)

A = percentage passing of Aggregate A for a sieve

b = proportion of Aggregate B in the mixture (in decimal or percentage)

B = percentage passing of Aggregate B for a sieve

c = proportion of Aggregate C in the mixture (in decimal or percentage)

C = percentage passing of Aggregate C for a sieve

NOTE: a + b + c = 1

From the given data it is observed that % Passing of Aggregate A and B is 0 % from 0.075 mm

sieve so A = 0 and B = 0 for that sieve and using the above-mentioned formula we can determine

c.

For 0.075 mm sieve

P = aA + bB + cC

⸫ …….. = 0 + 0 + c (…….)

⸫ c = …………



a + b + c = ………

⸫ a + b + ……… = ………

⸫ a + b = ………

⸫ a = ……… – b

For 2.36 mm sieve

P = aA + bB + cC

⸫ ……… = (……… - b) (………) + b (………) + ……… (………)

⸫ ……… = ………– ………b + ………b

⸫ ……… = ………b

⸫ b = ………

⸫ a = 0.75 – b = 0.75 – ………= ………


percentage passing values of Aggregate B by ……., multiply all the percentage passing values of

Aggregate C by …… and add all the three results for each sieve. Check the obtained values with

the range of desired gradation and mid-value.


Sieve size

(mm) 12.5 9.5 4.75 2.36 1.18 0.600 0.300 0.150 0.075

Desired

Gradation 100 70-90 45-65 30-60 25-50 19-36 8-25 4-12 3-6

% passing

Aggregate A

% passing

Aggregate B

% passing

Aggregate C

Mid value- P 100 80 55 45 37.5 27.5 16.5 8 4.5

Remarks



Keeping in view the remarks in above table further adjust the proportions of Aggregate A, B and

C

Adjusted proportion of Aggregate A: ……….

Adjusted proportion of Aggregate B: ……….

Adjusted proportion of Aggregate C: ……….


percentage passing values of Aggregate B by ……., multiply all the percentage passing values of

Aggregate C by ……. and add all the three results for each sieve. Check the obtained values with

the range of desired gradation and mid-value.


Sieve size

(mm) 12.5 9.5 4.75 2.36 1.18 0.600 0.300 0.150 0.075

Desired

Gradation 100 70-90 45-65 30-60 25-50 19-36 8-25 4-12 3-6

% passing

Aggregate A

% passing

Aggregate B

% passing

Aggregate C

Mid value- P 100 80 55 45 37.5 27.5 16.5 8 4.5

Remarks

RESULT:



4) For the same data as mentioned in exercise 3, find the proportions of Aggregate A, B and C by

using graphical method.

SOLUTION:

• Draw X and Y axes on a graph paper; X-Axis represents % Material Retained on 2.36 mm

sieve and Y-Axis represents % Material Passing from 0.075 mm sieve.

• Plot four points

o For Aggregate A, A (% material retained on 2.36 mm sieve, % material passing

from 0.075 mm sieve): A (…….. , ……..)

o For Aggregate B, B (% material retained on 2.36 mm sieve, % material passing

from 0.075 mm sieve): B (…….. , ……..)

o For Aggregate C, C (% material retained on 2.36 mm sieve, % material passing

from 0.075 mm sieve): C (…….. , ……..)

o For Mid-Value P, S (% material retained on 2.36 mm sieve, % material passing

from 0.075 mm sieve): S (…….. , ……..)

• Join the Points A and S; B and C by drawing a line segment.

• Extend line segment AS in such a manner that it touches the line segment BC and mark the

point where it coincides line segment BC as B’.

• Percentage proportion of aggregate A, a = 𝐇𝐨𝐫𝐢𝐳𝐨𝐧𝐭𝐚𝐥 𝐒𝐞𝐠𝐦𝐞𝐧𝐭 𝐒𝐁′

𝐇𝐨𝐫𝐢𝐳𝐨𝐧𝐭𝐚𝐥 𝐒𝐞𝐠𝐦𝐞𝐧𝐭 𝐀𝐁′ =

• Percentage proportion of aggregate C, c = (1 – a) 𝐕𝐞𝐫𝐭𝐢𝐜𝐚𝐥 𝐒𝐞𝐠𝐦𝐞𝐧𝐭 𝐁𝐁′

𝐕𝐞𝐫𝐭𝐢𝐜𝐚𝐥 𝐒𝐞𝐠𝐦𝐞𝐧𝐭 𝐁𝐂 =

• Percentage Proportion of aggregate B, b = 1 – a – c =



5) An aggregate mixture for Dense Bituminous Macadam Grade-II is to be prepared. So for the

same collect the sieves of sizes as specified in MoRT&H. Perform sieve analysis of four different

sizes of aggregates and determine the proportion of all four types of aggregates in which they are

to be mixed.


Sieve analysis of ………… mm aggregates; Sample Weight ………… g

IS Sieve Size in

mm

Weight Retain

(g)

% Weight

Retain

Cumulative %

Weight Retain

Cumulative %

Weight Passing


IS Sieve Size in

mm

Weight Retain

(g)

% Weight

Retain

Cumulative %

Weight Retain

Cumulative %

Weight Passing




IS Sieve Size in

mm

Weight Retain

(g)

% Weight

Retain

Cumulative %

Weight Retain

Cumulative %

Weight Passing


IS Sieve Size in

mm

Weight Retain

(g)

% Weight

Retain

Cumulative %

Weight Retain

Cumulative %

Weight Passing

Fill the cumulative percentage weight passing of all the aggregates as obtained in the preceding

tables in the following table (given after rough working space) and fix the proportions in such

a manner that the obtained gradation matches with in the range of desired gradation.



ROUGH WORKING SPACE:



TRIAL - I

IS

Sieve

Size

in

mm

% Weight

Passing of

………mm

Aggregates

% Weight

Passing of

………mm

Aggregates

% Weight

Passing of

………mm

Aggregates

% Weight

Passing of

………mm

Aggregates Obtained

Gradation

Desired

Gradation Proportion

(%)

……………...

Proportion

(%)

……………...

Proportion

(%)

……………...

Proportion

(%)

……………...

TRIAL - II

IS

Sieve

Size

in

mm

% Weight

Passing of

………mm

Aggregates

% Weight

Passing of

………mm

Aggregates

% Weight

Passing of

………mm

Aggregates

% Weight

Passing of

………mm

Aggregates Obtained

Gradation

Desired


(%)

……………...

Proportion

(%)

……………...

Proportion

(%)

……………...

Proportion

(%)

……………...




Comparison table of aggregate test

Specification Name of test

Impact Abrasion Crushing

value Shape Specific gravity and

water absorption Elongation Flakiness

Measure Toughness Hardness Strength Shape Shape Quality

Instrument

Impact

testing

machine

Loss angles

abrasion

machine Mould Length gauge Thickness gauge Pycnometer bottle or

Wire bucket

Brief

specification

Hammer-

13.5-14 kg

25 stock

Free fall

380mm

height

Steel

sphere

48mm dia.

Wt. 390 to

446 gm

Mould

15.2

cm

15 cm

Piston

Dimension > 9

5

200 Pieces

Dimension < 3

5

200 Pieces

Specific gravity range

2.2 to 3.2

Water absorption max.

allowable 2.0 %

Sample size

12.5 mm

passing,

10 mm retain

Grading

A,B,C,D = 5

Kg

E F and G

=10 Kg

12.5 mm

passing,

10 mm

retain

Test on minimum 200

pieces passing and retain

on respective sieve size

Test on minimum 200 pieces

passing and retain on

respective sieve size -

Sieve size used

Limiting

criteria

2.36 mm 1.7 mm 2.36 mm

Particle size smaller than

6.3 mm elongation test is

not applicable

Particle size smaller than 6.3

mm elongation test is not

applicable

-



Type of WorkMax. Lab Dry Unit Weight

when tested as per IS:2720 (Part 8)

Embankments up to 3m height, not

subjected to extensive floodingNot less than 15.2 kN/cu. m.

Grading

No.Size Range

IS Sieve

Size

% by Weight

Passing

Grading

Class

Size of

Screenings

IS Sieve

Size

% by Weight

Passing

Embankments exceeding 3m height

or embankments of any height

subject to long periods of inundation

Not less than 16 kN/cu. m. I II III IV V VI 75 mm 100 13.2 mm 10 53 mm 100

Subgrade and earthen

shoulders/verges,backfillNot less than 17.5 kN/cu. m. 75.0 mm 100 - - - 100 - 63 mm 90-100 11.2 mm 95-100 45 mm 95-100

53.0 mm 80-100 100 100 100 80-100 100 53 mm 25-75 5.6 mm 15-35 26.5 mm -

26.5 mm 55-90 70-100 55-75 50-80 55-90 75-100 45 mm 0-15 22.4 mm 60-80

Type of work/material

Relative Compaction as % of Max.

Lab Dry Density

as per IS:2720 (Part 8)9.50 mm 35-65 50-80 - - 35-65 55-75 22.4 mm 0-5 11.20 mm 40-60

Subgrade and earthen shoulders Not less than 97% 4.75 mm 25-55 40-65 10-30 15-35 25-50 30-55 63 mm 100 11.2 mm 100 4.75 mm 25-40

Embankment Not less than 95% 2.36 mm 20-40 30-50 - - 10-20 10-25 53 mm 95-100 9.5 mm 80-100 2.36 mm 15-30

0.85 mm - - - - 2-10 - 45 mm 65-90 5.6 mm 50-70600

micron8-22

a) Subgrade and 500 mm portion

just below the subgradeNot allowed 0.425 mm 10-15 10-15 - - 0-5 0-8 22.4 mm 0-10

b) Remaining portion of

embankment90-95% 0.075 mm <5 <5 <5 <5 - 0-3 11.2 mm 0-5

Specifications for Road - Earth Work, Sub-grade, Sub-Base and Base Course As per MORTH (Fifth Revision)

Granular Sub-Base Materials (GSB)Wet Mix

Macadam (WMM)

IS Sieve

Size

1 A

63 mm

to

45 mm

B

75 micron 0-5

Expansive Clays (Free swell index ≥ 50 %)

Grading Class

53 mm

to

22.4 mm

5-25

0-10

2

180

micron

13.2 mm

11.2 mm

180

micron

Compaction Requirements

IS Sieve

Size

% by Weight

Passing

Percent by Weight Passing the IS Sieve

Earth work, Embankment and Subgrade

Construction RequirementSub-Bases, Base Course and Shoulders (Non-Bituminous)

Grading Requirements

Water Bound Macadam (WBM)

Coarse Aggregates Screening Aggregates

Density Requirement

Department of Civil Engineering, Darshan Institute of Engineering & Technology, Rajkot



I.S. SOIL CLASSIFICATION ( IS 1498-1970) G= Gravel, S=Sand, C= Clay,M=Silt, W=Well graded, P= Poorly graded,L= Low compressibility, I= Intermediate compressibility, H=High compressibility,

O=Organic.

Major Division Group

symbol

Typical names Classification criteria Dual classification

Coarse grained

soil

More than 50% retained on 75μ

sieve

Gravel -More than 50%

retained on 4.75

mm sieve

Less than 5% passing through

75 μ sieve

GW Well graded gravels, Gravel sand mixtures with little

or no fines Cu>4 , Cc -1 to 3

% Passing between 5%

to 12% GW-GM

GW-GC

GP-GM GP-GC

GP Poorly graded gravel, Gravel sand mixtures with little

or no fines Not meeting above criteria

More than 12 % passing through

75 μ sieve

GM Silty gravels, Gravel, sand and silt mixtures, poorly

graded PI<4 PI between

4 and 7

GM-GC GC Clayey gravels, Gravel, sand and silt mixtures, poorly

graded PI>7

Sand -More

than 50% passing from

4.75 mm and

retained on 75 μ sieve

Less than 5% passing through

75 μ sieve

SW Well graded sand, Gravelly sands little or no fines Cu>6 , Cc -1 to 3 % Passing between 5%

to 12% SW-SM

SW-SC

SP-SM SP-SC

SP Poorly graded sand, Gravelly sand, little or no fines Not meeting above criteria

More than 12 %

passing through 75 μ sieve

SM Silty sand, poorly graded sand-silt mixtures PI<4 PI between

4 and 7 SM-SC SC Clayey sand, poorly graded sand-clay mixtures PI>7

Fine grained soil

More than 50%

passing from

75μ sieve

With low compressibility

WL < 35

ML In organic silt, silty or clayey fine sand, with low

plasticity,

CLASSIFICATION BASED ON PLASTICITY CHART

CL In organic clay, sand ,silty and clay mixtures with low

plasticity,

OL In organic silt

of low plasticity

With Intermediate compressibility

WL > 35 and WL < 50

MI In organic silt, silty or clayey fine sand of medium

plasticity

CI In organic clay, sandy clay, silty clayey of medium

plasticity

OI Organic silts and organic silty clay

of medium plasticity

With high compressibility

WL > 50

MH In organic silts, silty soil

of high compressibility

CH In organic clay


OH Organic clay


Highly organic soil Pt

Highly organic soil of high compressibility



SECTION-B

TESTS ON SOIL


7 California bearing ratio test (CBR test) IS:2720 Part 16 -1987

8 Dynamic cone penetrometer (DCP) test IRC: SP: 72-2015




CALIFORNIA BEARING RATIO TEST (IS: 2720 PART 16 - 1987)

OBJECTIVE:

• To determine the ratio which is expressed in percentage of force per unit area required

to penetrate a soil mass with a circular plunger of 50 mm diameter at the rate of 1.25

mm/min to that required for corresponding penetration in standard material.

• The ratio is determined for penetration of 2.5 and 5.0 mm.

• The CBR value of a soil is an index which up to some extent is related to its strength.

APPARATUS:

• CBR mould of height 175±0.1 mm and internal diameter 150±0.1 mm

• Extension collar of height 60 mm and internal diameter 150±0.1 mm

• A base plate of diameter 235±0.5 mm and having a suitable seating about 2 mm deep

on the top face for proper seating of the mould and the diameter of seating shall be 156

mm.

• Spacer disc of height 47.7 mm and diameter 148 mm and T-shaped handle for spacer

disc of 75 mm web and 115 mm flange.

• Penetration plunger of 50±0.1 mm diameter and height maximum 100 mm

• Expansion measuring equipment: Adjustable stem and perforated plates

• Annular weight and slotted weight of thickness to give 2.5 kg

• Loading machine equipped with a movable head or base which enables the plunger to

penetrate the specimen at a deformation rate of 1.25 mm/min.

• Dial gauge capable of measuring up to 0.01 mm

• IS sieve of size 19 mm and 4.75 mm sieve.

• Metal rammers of 2.6 kg or 4.89 kg



• Miscellaneous equipment’s such as a mixing bowl, straight edge, scales soaking tank

or pan, drying oven, filter paper and containers.

SAMPLE:

• The test may be performed on undisturbed specimens and

• Remoulded specimens which may be compacted either statically or dynamically.

UNDISTURBED SPECIMEN

• Undisturbed specimens shall be obtained by fitting to the mould, the steel cutting

edge of 150 mm internal diameter and pushing the mould as gently as possible into

the ground.

• This process may be facilitated by digging away soil from the outside as the mould is

pushed in.

• When the mould is sufficiently full of soil, it shall be removed by under digging, the top

and bottom surfaces are then trimmed flat so as to give the required length of specimen

ready for testing.

• If the mould cannot be pressed in, the sample may be collected by digging at a

circumference greater than that of the mould and thus bringing out a whole undisturbed

lump of soil.

• The required size of the sample to fit into the test mould shall then be carefully trimmed

from this lump.

• If the specimen is loose in the mud, the annular cavity shall be filled with paraffin wax

thus ensuring that the soil receives proper support from the sides of the mould during

the test.

• The density of the soil shall be determined either by weighing the soil with mould when

the mould is full with the soil, or by measuring the dimensions of the soil sample

accurately and weighing or by measuring the density in field in the vicinity of the spot

at which the sample is collected.



REMOULDED SPECIMEN

• The dry density for a remoulding shall be either the field density or the value of the

maximum dry density estimated by compaction tests. The water content used for the

compaction should be the OMC or the field moisture as the case may be.

• The material used in the remoulded specimen shall pass 19.0 mm IS sieve. Allowance

for larger material shall be made by replacing it bay an equal amount of material which

passes a 19.0 mm sieve and retained on 4.75 mm sieve.

• For Static Compaction the mass of wet soil at the required moisture content to give the

desired density when occupying the standard specimen volume in the mould shall be

calculated.

• A batch of soil shall be thoroughly mixed with water to give the required water content.

• The correct mass of moist soil shall be placed in the mould and compaction obtained by

pressing in the spacer disc, a filter paper being placed between the disc and the soil.

• For Dynamic Compaction, a representative sample of the soil weighing approximately

4.5 kg or more for fine grained soils and 5.5 kg or more for granular soils shall be taken

and mixed thoroughly with water.

• If the soil is to be compacted to the maximum dry density at the optimum moisture

content, then the exact mass of soil required shall be taken and necessary quantity

of water added so that the water content of the soil sample is equal to the

determined optimum water content.



COMPACTION PROCEDURE FOR REMOULDED SPECIMEN

Remoulded Specimen can be compacted by

Static Method Dynamic Method

Light Compaction Heavy Compaction

• Determine OMC and

MDD of sample

• Determine dry weight of

sample required to fill

the mould up to height of

12.5 mm.

• Mix water with soil

sample as per OMC.

• A disc of coarse filter

paper shall be placed on

the perforated base plate.

• Fill the mould with wet

soil sample and place

spacer disc on top of the

soil with the extension

collar attached.

• Apply compression

force on spacer disc

untill the top edge of the

mould and top of spacer

disc gets levelled.


MDD of sample




12.5 mm.


sample as per OMC

• Place spacer disc at

bottom of the mould.

• Attach the extension

collar at the top of

mould.


soil sample in 3 layers.

• Each layer is compacted

by giving 55 blows of

rammer.

• Weight of rammer shall

be 2.6 kg and free fall

height of 31 cm.


MDD of sample




12.5 mm.


sample as per OMC

• Place spacer disc at

bottom of the mould.

• Attach the extension

collar at the top of

mould.


soil sample in 5 layers.

• Each layer is compacted

by giving 55 blows of

rammer.

• Weight of rammer shall

be 4.89 kg and free fall

height of 45 cm.

• After compaction the extension collar shall be removed, and the compacted soil carefully

trimmed even with the top of the mould by means of a straightedge.

• Any hole that may then develop on the surface of the compacted soil by the removal of

coarse material, shall be patched with smaller size material; the perforated base plate and the

spacer disc shall be removed, and the mass of the mould and the compacted soil specimen

recorded.

• A disc of coarse filter paper shall be placed on the perforated base plate and in the case of

dynamic compaction, the mould and the compacted soil shall be inverted and the perforated

base plate clamped to the mould with the compacted soil in contact with the filter paper.

• In both cases of compaction, if the sample is to be soaked, representative samples of the

material at the beginning of compaction and another sample of the remaining material after

compaction shall be taken for determination of water content. Each water content sample

shall weigh not less than about 50 g.

• If the sample is not to be soaked, a representative sample of material from one of the cut-

pieces of the material after penetration shall be taken to determine the water content. In all

cases, the water content shall be determined.



TEST PROCEDURE FOR SWELLING TEST:

• A filter paper shall be placed over the specimen and the adjustable stem and perforated plate

shall be placed on the compacted soil specimen in the mould.

• Weights to produce a surcharge equal to the weight of base material and pavement to the

nearest 2.5 kg shall be placed on the compact soil specimen.

• The whole mould and weights shall be immersed in a tank of water allowing free access of

water to the top and bottom of the specimen. The tripod for the expansion measuring device

shall be mounted on the edge of the mould and the initial dial gauge reading recorded.

• This set-up shall be kept undisturbed for 96 hours noting down the readings every day against

the time of reading. A constant water level shall be maintained in the tank through-out the

period.

• At the end of the soaking period, the change in dial gauge shall be noted, the tripod removed,

and the mould taken out of the water tank.

• The free water collected in the mould shall be removed and the specimen allowed to drain

downwards for 15 minutes. Care shall be taken not to disturb the surface of the specimen

during the removal of the water.

• The weights, the perforated plate and the top filter paper shall be removed and the mould

with the soaked soil sample shall be weighed and the mass recorded.

TEST PROCEDURE FOR PENETRATION TEST:

• The mould containing the specimen, with the base plate in position but the top face exposed,

shall be placed on the lower plate of the testing machine.

• Surcharge weights, enough to produce an intensity of loading equal to the weight of the base

material and pavement shall be placed on the specimen.

• If the specimen has been soaked previously, the surcharge shall be equal to that used during

the soaking period.

• To prevent upheaval of soil into the hole of the surcharge weights, 2.5 kg annular weight

shall be placed on the soil surface prior to seating the penetration plunger after which the

remainder of the surcharge weights shall be placed.

• The plunger shall be seated under a load of 4 kg so that full contact is established between

the surface of the specimen and the plunger. The load and deformation gauges shall then be

set to zero (In other words, the initial load applied to the plunger shall be considered as zero

when determining the load penetration relation).



• Load shall be applied to the plunger into the soil at the rate of 1.25 mm per minute. Reading of

the load shall be taken at penetrations of 0.5, 1.0, 1.5, 2.0, 2.5, 4.0, 5.0, 7.5, 10.0 and 12.5 mm

(The maximum load and penetration shall be recorded if it occurs for a penetration of less than

12.5 mm).

• The plunger shall be raised, and the mould detached from the loading equipment. About 20 to

50 g of soil shall be collected from the top 30 mm layer of the specimen and the water content

is determined.

• If the average water content of the whole specimen is desired, water content sample shall be

taken from the entire depth of the specimen.

• The undisturbed specimen for the test should be carefully examined after the test is completed

for the presence of any oversize soil particles which are likely to affect the results if they happen

to be located directly below the penetration plunger.

OBSERVATIONS:

SPECIMEN DATA

• The specimen data includes the condition of specimen at the time of testing, type of compaction

adopted, the amount of soil fraction above 20 mm that has been replaced and the water content

and density determinations before and after the mould has been subjected to soaking.



PENETRATION DATA

• The readings for the determination of expansion ratio and the load penetration data shall

be recorded.

LOAD PENETRATION CURVE

• The load penetration curve shall be plotted. This curve is usually convex upwards although

the initial portion of the curve may be convex downwards due to surface irregularities.

• A correction shall then be applied by drawing a tangent to the point of greatest slope and

then transposing the axis of the load so that zero penetration is taken as the point where the

tangent cuts the axis of penetration.

• The corrected load-penetration curve would then consist of the tangent from the new origin

to the point of tangency on the re-sited curve and then the curve itself, as illustrated in

figure below.



SOIL SAMPLE DETAILS

Sr.

No. Details

For Dynamic

Compaction

For Static

Compaction

1 Optimum water content, w (%)

2 Weight of empty mould, A (g)

3 Weight of mould + compacted specimen, B (g)

4 Weight of compacted

Specimen, C = B – A (g)

4 Volume of specimen, V (m3)

5 Bulk density, γb (g/cc) = V/C

6

Dry density,

γd (g/cc) = γb / [1 + (w/100)]

7 Period of soaking (If soaked sample)

LOAD PENETRATION READINGS

Proving Ring Capacity: …………………. kN

Calibration Factor of Proving Ring: …………………. kg / Ring Division

Surcharge Weight: …………………… kg

Least Count of Dial Gauge for measuring penetration: ……………. mm / Ring Division

CALCULATIONS:

Expansion Ratio = [(dt - ds)/h] X 100 =

Where, dt = final dial gauge reading in mm,

ds = initial dial gauge reading in mm, and

Penetration

in mm Proving Ring’s Dial Gauge Ring Division

Load in

kg

Corrected

Load in kg

0.0

0.5

1.0

1.5

2.0

2.5

4.0

5.0

7.5

10.0

12.5



h = initial height of the specimen in mm

The expansion ratio is used to qualitatively identify the potential expansiveness of the soil.

California Bearing Ratio

The CBR values are usually calculated for penetrations of 2.5 and 5.0 mm. Corresponding to

the penetration value at which the CBR values is desired, corrected load value shall be taken

from the load penetration curve and the CBR calculated as follows:

California Bearing Ratio (%) = (PT/PS) x 100

Where, PT = corrected unit (or total) test load corresponding to the chosen penetration from

the load penetration curve, and

PS = unit (or total) standard load for the same depth of penetration as for PT taken from

the below table

CBR at 2.5 mm Penetration =

CBR at 5.0 mm Penetration =

Generally the C.B.R. value at 2.5 mm will be greater that at 5 mm and in such a case/the former shall be taken

as C.B.R. for design purpose. If C.B.R. for 5 mm exceeds that for 2.5 mm, the test should be repeated. If identical

results follow, the C.B.R. corresponding to 5 mm penetration should be taken for design.

STANDARD LOAD

Penetration of plunger

(mm) Standard load (kg)

2.5 1370

5.0 2055

7.5 2630

10.0 3180

12.5 3600

CONCLUSION:



EXERCISE: 1) Draw a neat sketch of CBR apparatus as shown in the test procedure.

2) A sub grade soil sample was tested using standard CBR test apparatus and observations

are given below. Assume that the load penetration curve in convex throughout. What will

be the CBR value in % for the given sample?

Load in Kg Penetration in mm

60.5 2.5

80.5 5.0





DYNAMIC CONE PENETROMETER TEST (IRC: SP: 72-2015)

OBJECTIVE:

• To evaluate strength of subgrade and other unbound pavement layers on site.

APPARATUS:

• DCP test apparatus consists of steel cone with an angle of 60o having diameter of

20 mm, standard 8 kg drop hammer slides over a 16 mm diameter steel rod with a

fall height of 575 mm.



TEST PROCEDURE:

• One person holds the DCP instrument in a vertical position; another person carefully drops

the weight and third takes the readings of penetration.

• The penetration of the cone can be measured on a graduated scale. The readings are taken

with each blow of the weight.

• The field data is reduced in terms of penetration versus corresponding number of blows. The

number of blows and depth readings are recorded on the DCP test form.

• The cone is case-hardened but requires replacing. When used on subgrade materials the cone

can be expected to last 30 to 40 tests before replacement.

OBSERVATION TABLE:

No.

of

blow

Penetration

in

mm/blow

Cumulative

Penetration

in mm

CBR (%) as per

Equation:

Log10CBR = 2.465 – 1.12

Log10N

Modulus of Subgrade

(MPa):

Esubgrade = 357.87 x (DCP)-

0.6445

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

Avg.: Avg.: Avg.:



The following shows the relationship between CBR (%) and DCP (mm/blow)

CBR value for Average penetration in mm/blow as per graph is ………..




Working with

Bituminous Mix

Temp.

°C

Tests on

Bitumen/Mix

- 200 -Nominal

Agg. Size

37.5

mm

26.5

mm

Nominal

Agg. Size19 mm 13.2 mm

- 175Minimum Flash

Point

Bitumen

Viscosity

Grade

Bitumen

Temperature

Aggregate

Temperature

Mixed

Material

Temperature

Laying

Temperature

*Rolling

Temperature

Layer

Thickness

75-100

mm

50-75

mm

Layer

Thickness50 mm

30-40

mm

VG 10 VG 20 VG 30 VG 40Mixing Temperature

Range (150 to 177)163 TFO & RTFO tests VG 40 160-170 160-175 160-170 150 Min. 100 Min. IS Sieve IS Sieve

Hot

Climate

Cold

Climate

Absolute Viscosity at

60° C, Poises, Min. 800-1200 1600-2400 2400-3600 3200-4800Compaction

Temperature135

Kinematic Viscosity

testVG 30 150-165 150-170 150-165 140 Min. 90 Min. 45 mm 100 - 45 mm - - Compaction level

Kinemaic viscosity at

135°C,cSt,Min. 250 300 350 400Minimum Rolling

Temperature100 - VG 20 145-165 145-170 145-165 135 Min. 85 Min. 37.5 mm 95-100 100 37.5 mm - -

Minimum stability

(kN at 60 °C)9.0 12.0 10.0

AASHTO

T245

Flash point,°C, Min. 220 220 220 220 60

Static Viscosity,

Marshall Stability &

Float testsVG 10 140-160 140-165 140-160 130 Min. 80 Min. 26.5 mm 63-93 90-100 26.5 mm 100 -

Marshall flow

(mm)2-4 2.5-4 3.5-5

AASHTO

T245

Solubility in

trichloroethylene,

Min. %99 99 99 99 27

Ductility & Specific

Gravity test19 mm - 71-95 19 mm 90-100 100

Marshall Quotient

(Stability/Flow)2-5

MS-2 and

ASTM D2041

Penetration at 25°C,

100g, 5s, 0.1 mm 80 60 45 35 25Needle

Penetration test13.2 mm 55-75 56-80 13.2 mm 59-79 90-100 % Air voids

Softening Point,

°C, Min. 40 45 47 50 4Needle

Penetration test

Bitumen

Emulsion

Type of

Surface

Rate of

Spray (kg/sq. m.)

9.5 mm - - 9.5 mm 52-72 70-88% Voids Filled

with Bitumen

(VFB)

0Rate of

Spray (kg/sq. m.)

Type of

Cutback

Rate of

Spray (kg/sq. m.)

Bituminous

surfaces0.20-0.30 4.75 mm 38-54 38-54 4.75 mm 35-55 53-71

Coating of

Aggregate

Particle

IS:6241

Viscosity ratio at

60°C, Max.4 4 4 4 -10 WMM/WBM 0.7-1.0 MC 30 0.6-0.9

Granular

surfaces treated

with primer

0.25-0.30 2.36 mm 28-42 28-42 2.36 mm 28-44 42-58Tensile Strength

Ratio

AASHTO

T283

Ductility at

25°C, cm, Min75 50 40 25 - -36

Stabilized soil

bases/Crusher

Run Macadam

0.9-1.2 MC 70 0.9-1.2

Cement

Concrete

Pavement

0.30-0.35 1.18 mm - - 1.18 mm 20-34 34-48

0.6 mm - - 0.6 mm 15-27 26-38

0.3 mm 7-21 7-21 0.3 mm 10-20 18-28

VG 10 80/100 ≤ 30 °C ≤ 1500 CVPDBM, DBM and

BC

VG 20 60/80 ≤ 30 °C ≤ 1500 CVPDBM, DBM and

BC

3.0 4.0

26.5 11.0 12.0

37.5 10.0 11.0

Spraying applications, paving applications in

cold regions.

Paving applications in cold climatic conditions of

North India and in high altitude region.

Use in high stressed area like intersections, toll

plazas, truck terminals.

Paving applicaions for most part of India.

VG 40

VG 30

Minimum VMA Percent Related to

Design Percentage Air Voids

Bitumen

Content %

by mass of

total mix

Min. 4.0 Min. 4.5

Bitumen

Content %

by mass of

total mix

Min. 5.2 Min. 5.4

0.075 mm 2-8

BM, DBM,

SDBC and BC

DBM,SDBC

and BC

Maximum

average air

temperature °C

≤ 40 °C

≥ 40 °C

Traffic (CVPD)

For all types of

traffic

Heavy loads,

Expressways,

MSA > 30

-0.15 mm

Base/Binder Course

± 7%Aggregate passing 13.2 mm, 9.5 mm sieve

2-8 0.075 mm 2-8 4-10

12-205-130.15 mm-

± 6%

± 5%

± 4%

± 2%

± 0.3% & ± 10°C

Aggregate passing 4.75 mm sieve

Aggregate passing 2.36 mm, 1.18 mm, 0.6 mm

Aggregate passing 0.3 mm, 0.15 mm sieve

Aggregate passing 0.075 mm sieve

Binder content & Mixing temperature

± 8%

Permissible Variations in the Actual Mix from the

Job Mix Formula (JMF)

Description

Aggregate passing 19 mm sieve or larger

Selection of Binder for Bituminous Mixes & its Applications in India

Viscosity Grade General ApplicationsBituminous

Course

Specifications for Road - Bases and Surface Courses (Bituminous) As per IRC/MORTH - Fifth Revision

Requirements for Paving BitumenMixing, Laying and Rolling

Temperatures for

Bituminous Mixes °C

3-5

Cumulative % by

weight of total

aggregate passing

Working Range of

Bituminous

Pavements in

India (60 to -10)

Direct tensile and

Frass break point

tests, Min. Frass

breaking point for

Indian conditions

= - 4 to -10

Working and Testing

Temperature of Bitumen/Mix

*Rolling must be completed before the mat cools to these

minimum temperatures

Bitumen

Properties

Bitumen Grade

13.0

12.0

Nominal

Maximum

Particle Size

(mm)

5.0

*Minimum Percent Voids in

Mineral Aggregate (VMA)

Rate of Application of Prime Coat

Type of

Surface

Bitumen Cutback

Rate of Application

of Tack Coat

Test on Residue from Thin Film Oven Tests (TFOT) / RTFOT

60/70

30/40

Equivalent

Penetration

Grade

Gradation Requirement

Bituminous Concrete

(BC)

Dense Graded

Bituminous Macadam

(DBM)

Requirements of Mixture for

Dense Graded Bituminous

Macadam (DBM) &

Bituminous Concrete (BC)

% Voids in

Mineral

Aggregate

Minimum percent voids in mineral aggregate

(VMA) are set out in table below*

80% Minimum

Viscosit

y Grade

Paving

Bitumen

Modified

Bitumen Test

Method

95% Minimum

65-75

2.5-5

75 blows on each face of the specimen

PropertiesCumulative % by

weight of total

aggregate passing

Department of Civil Engineering, Darshan Institute of Engineering & Technology, Rajkot


Highway Engineering Lab Manual (2150601) Sem.-V Civil Engineering Page 68

SECTION-C

TEST ON BITUMEN AND BITUMINOUS MIX DESIGN

Sr. No. Name of Test Relevant IS code

CONSISTENCY TESTS OF BITUMEN

9 Penetration test IS: 1203-1978

10 Softening point test IS: 1205-1978

11 Introduction of tar viscometer IS: 1206-1978 (Part-I)

12 Viscosity test- Absolute Viscosity IS: 1206-1978 (Part-II)

13 Viscosity test – Kinematic Viscosity IS: 1206-1978(Part-III)

AGING TESTS ON BITUMEN

14 Introduction on Thin film oven test ASTM-D-1754/IS: 9382

SAFETY TESTS ON BITUMEN

15 Flash and Fire point test IS: 1209-1978

OTHER TESTS

16 Specific Gravity test on bitumen IS: 1202-1978

17 Ductility test IS: 1208-1978




BITUMEN PENETRATION TEST (IRC: 1203 - 1978)

The penetration of a bituminous material is the distance in tenths of a millimeter that a

standard needle will penetrate vertically into a sample of the material under standard

conditions of temperature, load and time.

OBJECTIVE:

• To determine penetration of asphaltic bitumen.

APPARATUS:

• Container - A metal or glass cylinder, flat bottom container of essentially the

following dimensions shall be used:

o For penetrations below 225:

▪ Diameter: 55 mm

▪ Internal Depth: 35 mm

o For penetrations between 225 and 350:

▪ Diameter: 70 mm

▪ Internal Depth: 45 mm

• Needle - A straight highly polished, cylindrical, stainless steel rod, with conical and

parallel portions co-axial, having the shape, dimensions and tolerances given in the

following figure. The needle is provided with a shank approximately 3 mm in

diameter into which it is movable fixed.

• Water Bath – A water bath preferably with a thermostat maintained at 25 ± 0.1oc

not less than 10 litres of water, the sample being immersed to a depth of not less

than 100 mm from the top and supported on a perforated shelf not less than 50 mm

from the bottom of the bath.

• Transfer Dish – A small dish, provided with some means which ensure a firm

bearing and prevent the rocking of the container and of such a capacity as will

ensure complete immersion of the container during the test.

• Penetration Apparatus – Any apparatus which allow the needle to penetrate

without appreciable friction, and which is accurately calibrated to yield results in

tenths of millimeter shall be adopted.



• Thermometer – Range 0 to 50oC

• Timing Device – Any convenient timing device, such as electric timer, stopwatch

accurate to within ±0.1 s for a 60 s interval.

SAMPLE:

• Soften the material to a pouring consistency at a temperature not more than 60°C for tars

and pitches and not more than 90°C for bitumen above the respective approximate

softening point and stir it thoroughly until it is homogeneous and is free from air bubbles

and water.

• Pour the melt into the container to a depth at least 10 mm in excess of the expected

penetration.

• Protect the sample from dust and allow it to cool in an atmosphere at a temperature

between 15 to 30°C for 11

2 h to 2 h for 45 mm deep container and 1 to 1

1

2 ℎ when the

container of 35 mm depth is used.

• Then place it along with the transfer dish in the water bath at 25.0 ± 0.1 °C and allow it

to remain for 11

2 h to 2 h and 1 to 1

1

2 h for 45 mm and 35 mm deep container

respectively.



TEST PROCEDURE:

• Unless otherwise specified, testing shall be carried out at 25.0 ± 0.1oC.

• Fill the transfer dish with water from the water bath to a depth sufficient to cover the

container completely; place the sample in it and put it upon the stand of the penetration

apparatus.

• Adjust the needle (previously washed clean with benzene, carefully dried, and loaded

with the specified weight) to contact the surface of the sample.

• This may be accomplished by placing the needle point in contact with its image reflected

by the surface of the material from a suitably placed source of light.

• Unless otherwise specified, load the needle holder with the weight required to make a

total moving weight (the sum of the weights of the needle, carrier and superimposed

weights) of 100 ± 0.25 g.

• Note the reading of the dial or bring the pointer to zero. Release the needle and adjust

the points, if necessary, to measure the distance penetrated.

• Make at least three determinations at points on the surface of the sample not less than

10 mm apart and not less than 10 mm from the side of the dish.

• After each test, return the sample and transfer dish to the water bath, and wash the needle

clean with benzene and dry.

• In the case of material of penetration greater than 225, three determinations on each of

two identical test specimens using a separate needle for each determination shall be

made, leaving the needle in the sample on completion of each determination to avoid

disturbance of the specimen.

• For determining the penetration ratio, testing shall also be carried out a 4.0° ± 0.1°C.

• For test at 4°C the total weight on the penetration needle shall be 200 ± 0.25 g and the

time of penetration shall be 60 s.

OBSERVATION:

Bitumen Grade:

Depth of Sample:

Test Temperature:

Bitumen Pouring Temp °C:

Bath Material:

Period of Air Cooling:

Period up to which the sample is kept in Water Bath:



Reading

No.

Penetration Value (1/10th of mm) Mean Penetration

Value

(1/10th of mm)

Initial

Reading

Final

Reading Difference

1

2

3

EXERCISE:

1) ………….. g weight must be loaded with the needle for penetration test.

2) The test temperature for bitumen penetration test as per IS 1203-1978 is………….°C

3) 60/70 penetration grade bitumen when tested for penetration must give value in

between …………. and ………….

4) Minimum penetration value for VG30 grade of bitumen is……….as per IS 73-2013.

5) Draw a neat sketch of Bitumen Penetrometer showing all the components.





BITUMEN SOFTENING POINT TEST (IRC: 1203 - 1978)

The temperature at which the substance attains a particular degree of softening under

specified condition of test.

OBJECTIVE:

• To determine softening point of asphaltic bitumen.

APPARATUS:

• Ring and Ball Apparatus: A convenient form of apparatus as shown in the figure

below.

• Steel Balls: 2 Numbers; each 9.5 mm in diameter and weighing 3.5 ± 0.05 g.

• Brass Rings: 2 Numbers; the rings shall be tapered and shall conform to the

following dimensions:

o Depth: 6.4 ± 0.1 mm

o Inside Diameter at Bottom: 15.9 ± 0.1 mm

o Inside Diameter at Top: 17.5 ± 0.1 mm

o Outside Diameter: 20.6 ± 0.1 mm

• Ball Guide: A convenient form of ball centering guide as shown in figure below:

Thermometer

Support System

Steel Ball

Brass Ring



• Support: Any means of supporting the rings may be used provided the following

conditions are observed:

o The rings shall be supported in a horizontal position with the upper surface

of the rings 50 mm below the surface of the bath liquid.

o There shall be exactly 25 mm between bottom of the rings and the top

surface of the bottom plate of the support, if any, or the bottom of the bath.

o The thermometer shall be suspended so that the bottom of the bulb is level

with the bottom of the rings, and within 10 mm of the rings, but not

touching them.

• Thermometer: It shall be of the range -2oC to 80oC

• Bath: A heat resistance glass vessel not less than 85 mm in diameter and 120 mm in

depth. The bath liquid shall be boiled with distilled water when testing materials

having softening points below 80oC, and pure glycerine for materials having

softening points above 80oC.

• Stirrer: Manual or mechanical, which always operates smoothly to ensure uniform

heat distribution throughout the bath.



SAMPLE:

• Heat the material to a temperature between 75oC and 100oC above its softening

point, stir until it is completely fluid and free from air bubbles and water, and filter,

if necessary, through IS Sieve 30.

• Place the rings, previously heated to a temperature approximating to that of the

molten material, on a metal plate which has been coated with a mixture of equal

parts of glycerine and dextrine, and fill with sufficient melt to give an excess above

the level of the ring when cooled.

• After cooling for 30 minutes in air, level the material in the ring by removing the

excess with a warmed, sharp knife.

TEST PROCEDURE:

• For Materials of Softening Point Below 80o, Assemble the apparatus with the

rings, thermometer and ball guides in position, and fill the bath to a height of 50

mm above the upper surface of the rings with freshly boiled distilled water at a

temperature of 5oC.

• Maintain the bath at a temperature of 5oC for 15 minutes after which place a ball,

previously cooled to a temperature of 5oC, by means of forceps in each ball guide.

• Apply heat to the bath and stir the liquid so that the temperature rises at a uniform

rate of 5.0 ± 5oC per minute until the material softens and allows the ball to pass

through the ring.

• The rate of temperature rise shall not be averaged over the period of test, and any

test in which the rate of temperature rise does not fall within the specified limits

after three minutes shall be rejected.

• Make determination in duplicate.

• For Materials of Softening Point Above 80o, the procedure is like that described

above with the difference that glycerine is used in place of water in the bath and the

starting temperature of the test is 35oC.

• Make the determination in duplicate.

REPORTING OF RESULT:

• Record for each ring and ball, the temperature shown by the thermometer at the

instant the sample surrounding the ball touches the bottom plate of the support, if

any, or the bottom of the bath.

• Report to the nearest 0.5oC the mean of the temperature recorded in duplicate

determinations, without correction for the emergent stem of the thermometer, as the

softening point.



OBSERVATION:

Bitumen grade:

Period of air cooling:

Medium of liquid bath:

Test starting temperature:

Period up to which starting temperature of test is maintained:

Rate of heating:

Bitumen pouring temp °c:

Description For Ball 1 For Ball 2 Mean Value

Temperature at which the

bitumen around the ball

touches the bottom as the

ball falls

EXERCISE:

1) Suggest the softening point for following grades of bitumen:

VG 10: ……… oC

VG 20: ……… oC

VG 30: ……… oC

VG 40: ……… oC



2) Which liquid medium shall be used as liquid bath for determination of

softening point of materials whose approximate softening point is above

80oC? ………………………..

3) The rate at which bitumen sample is heated during softening point test is

……………….

4) Draw a neat sketch of ring and ball apparatus showing all the components.





BITUMEN VISCOSITY TEST (IRC: 1206-1978: Part-1 INDUSTRIAL

VISCOSITY)

The property of a fluid by which it resists flow due to internal friction, and one of the

methods by which it is measured, is by determining the time taken by 50 cc of the material

to flow from a cup through a specified orifice under standard conditions of test and at

specified temperature.

OBJECTIVE:

• To determine viscosity of bitumen, road tar and cutback bitumens.

APPARATUS:

• Tar Viscometer - consists essentially of a cup having a specified orifice and valve; a

water bath mounted on three legs having a suitable sleeve for the cup, a stirrer, a

shield and a receiver. The following is the detailed description of the different parts

and accessories of tar viscometer:

o Cup - known as the 10 mm cup. The bottom of the cup consists of a circular

phosphor-bronze plate screwed into the cylinder and made conical to facilitate

drainage of the tar after use. It is provided centrally with a extension which is

drilled and polished internally to give a 10-mm circular orifice. The upper rim

of the orifice shall be perfectly circular in order to provide a seating for the

valve.

o Valve - It serves to close the orifice of the 10 mm cup.

o Water bath - The water bath is mounted on three equidistant legs which are

riveted to the cylindrical wall of the bath and are of sufficient length to permit

a 100-ml cylinder to be placed below the orifice of the cup.

o Sleeve - to receive the cup and to hold it in position with an easy sliding fit.

o Stirrer - consists of four vertical vanes, with the upper and lower portions

turned in opposite directions, mounted on a cylinder which slips on the sleeve

with an easy sliding fit.

o Curved shield - fixed to the upper edge of the cylinder and extends to within

about 5 mm of the walls of the water bath. This shield carries an insulated

handle for rotating the stirrer, a support for a thermometer, and a swivelled

support for the valve.

o Receiver - a 100-ml graduated measuring cylinder with graduations at 20 ml,

25 ml and 75 ml capacities, having an internal diameter of not more than 29

mm.

o Thermometers - Two standard thermometers, one for the bath and another for

the cup. Both the thermometers shall be of the same range, depending on the

temperature at which the determination is being made.



TEST PROCEDURE:

• Adjust the tar viscometer so that the top of the tar cup is level. Heat the water in the

water bath to the temperature specified for the test and maintain it within ± 0.l°C of

the specified temperature throughout its bulk for the duration of the test, the stirrer

being gently rotated at frequent intervals or, preferably, continuously.

• Clean the tar cup orifice of the viscometer with a suitable solvent and dry thoroughly.

• Warm and stir the material under examination to 20oC above the temperature

specified for the test, and cool, while continuing the stirring. When the temperature

has fallen to slightly above the specified temperature, pour the tar into the tar cup

until the levelling peg on the valve rod is just immersed when the latter is vertical.

• Pour into the graduated receiver 20 ml of mineral oil, or a one percent by weight

solution of soft soap, and place it under the orifice of the tar cup.

• Place a second standard thermometer in the tar and stir the latter until the temperature

is within ± 0.1oC of the specified temperature. When this temperature has been

reached, suspend the thermometer co-axially with the cup and with its bulb

approximately at the geometric centre of the tar.



• Allow the assembled apparatus to stand for five minutes during which period the

thermometer reading shall remain within 0.05°C of the specified temperature.

Remove the thermometer and quickly remove any excess of tar so that the final level

is on the centre line of the levelling peg when the valve is in vertical position.

• Lift the valve and suspend it on the valve support. Start the stop watch or the time

recording device when the reading in the cylinder is 25 ml and stop it when it is i5

ml. Note the time in seconds.

REPORTING OF RESULT:

• Report the time in seconds taken by 50 ml of the tar to flow out as the viscosity of

the sample at the temperature specified for the test.

• State clearly whether the sample was dried or tested as received as the presence of

water, particularly in quantities less than one percent, has a marked effect on the

viscosity. Report the method of drying adopted.

• The results of repeat determinations on portions of the same sample shall fall within

±4 percent of the average of several readings.

NOTE:

• The working range of the instrument with the 10 mm cup is such that the time of

efflux shall be between 10 and 140 seconds.

• The temperature of test shall be appropriate to emulate the condition specified and

shall be a multiple of 5°C, not lower than 20°C.

• The tar cup is a critical part of a viscometer and special precautions shall be observed

in its treatment and use. Any cleaning process shall be of gentle nature.

• The orifice of the tar cup shall be tested at frequent intervals with a gauge having

appropriate diameters.

TEST TEMPERATURE & VISCOSITY OF DIFFERENT GRADES OF ROAD TAR

Road Tar type RT-1 RT-2 RT-3 RT-4 RT-5

Orifice size, mm 10 10 10 10 10

Test temperature 35°C 40°C 45°C 55°C 65°C

Viscosity in sec. 30-55 30-55 35-60 40-60 40-60

DISCUSSION:

The working range of tar viscometer for 10 mm orifice is 10 to 140 seconds. For

cutback bitumen, the orifice size specified is 4mm for lower grades and 10mm for higher

grades with higher viscosity.




BITUMEN VISCOSITY TEST (IRC: 1206-1978: Part-2 ABSOLUTE

VISCOSITY)

Absolute or Dynamic Viscosity of Bitumen is an internal friction, such that if a tangential

force of one dyne (0.00001 N) acting on planes of unit area separated by unit distance of

the liquid produces unit tangential velocity, the cgs unit for the viscosity of the liquid is 1

poise.

OBJECTIVE:

• To determine viscosity of of paving grade and cut-back bitumens.

APPARATUS:

• Viscometer – Capillary type made of borosilicate glass.

o Cannon-Manning Vacuum Viscometer (sample & test procedure

explained for this viscometer only)

o Asphalt Institute Vacuum Viscometer

o Modified Koppers Vacuum Viscometer

• Thermometer of range 0oC to 150oC

• Bath: A suitable bath for immersion of the viscometer so that the liquid reservoir or

top of the capillary, whichever is uppermost is at least 20 mm below the upper bath

level, and with the provision for the visibility of the viscometer and the thermometer.

• Vacuum System: A vacuum system capable of maintaining a vacuum to within ±

0.05 cm of the desired level up to and including 30 cm of mercury.

• Timing Device: A stopwatch or stop clock capable of being read up to half a second.

• Viscometer Holder

SAMPLE:

• Heat the sample to a temperature not more than 60°C for the tars and pitches and

not more than 90°C for bitumen’s above their respective approximate softening

point temperature respectively until it has become sufficiently fluid to pour.

• Transfer about 20 ml into a suitable container and maintain it to a temperature of

135 ± 5.5oC stirring occasionally to prevent local overheating and allow the

entrapped air to escape.

• Charge the viscometer by pouring the prepared sample to within ± 2 mm of fill line

E. Place the charged viscometer in an oven or bath maintained at 135 ± 5.5oC for a

period of 10 ± 2 mins to allow larger air bubble to escape.



CANNON-MANNING VACUUM CAPILLARY VISCOMETER



TEST PROCEDURE:

• Maintain the bath at the test temperature within ± O.1°C.

• Place the charged viscometer vertically in the water bath with the help of a holder so

that the uppermost timing mark is at least 2 cm below the surface of the bath liquid.

Establish a vacuum of 30 ± 0.05 mm of mercury in the vacuum system and connect it

to the viscometer with the valve closed.

• After the viscometer has remained in the bath for 30 ± 5 min open the valve and allow

the asphalt to flow into the viscometer. Measure to within ± 0.5 s the time required for

the leading edge of the meniscus to pass between successive pairs of timing marks.

• Upon completion of the test, remove the viscometer from the bath and place it in an

inverted position in an oven maintained at 135 ± 5°C until asphalt is drained off

thoroughly from the viscometer.

• Clean the viscometer thoroughly by rinsing several times with an appropriate solvent

completely. Dry the tube by passing a slow stream of filtered dry air through the

capillary for 2 minutes.

• Periodically clean the instrument with chromic acid to remove organic deposits. Rinse

thoroughly with distilled water and acetone and dry with clean air.

CALCULATION:

• Calculate and report the absolute viscosity to three significant figures, by the

following equation:

o Viscosity Poises = Kt

Where, K = selected calibration factor, in poise per second; and

t = flow time, in seconds

OBSERVATION:

Grade of Bitumen:

Test Temperature:

Parameter

For Bulb B For Bulb C

Flow Time, Seconds (FT)

Calibration Factor (CF)

Viscosity in Poise (FT x CF)

Out of the flow time in seconds for Bulb B and C, consider the time which is more than 60 seconds

for viscosity calculation.



CONCLUSION:

EXERCISE:

1) Prior to testing, the viscometer filled with sample is placed in the liquid bath maintained

at temperature ………………….oC for a period of …………….. mins.

2) Absolute viscosity must be carried out at …………….oC

3) A vacuum pressure of …………….. is applied to facilitate bitumen to flow through the

bulbs of viscometer.





BITUMEN VISCOSITY TEST (IRC: 1206-1978: Part-3 KINEMATIC

VISCOSITY)

Kinematic Viscosity of Bitumen is defined as the quotient of the absolute or dynamic

viscosity divided by the density of the liquid under test; both at the same temperature. The

cgs unit of kinematic viscosity is the stoke which has the dimensions square centimetre per

second. For petroleum products the kinematic viscosity is generally expressed in

centistokes (sSt) which is 1/100 th of a stoke.

OBJECTIVE:

• To determine viscosity of paving grade and cut-back bitumens.

APPARATUS:

• Viscometer – Capillary type made of borosilicate glass.

o Cannon-Fenske Viscometer for Opaque Liquids.

o BS U-Tube Modified Reverse Flow Viscometer

• Thermometer of range 0oC to 150oC

• Bath: A suitable bath for immersion of the viscometer so that the liquid reservoir or

top of the capillary, whichever is uppermost is at least 20 mm below the upper bath

level, and with the provision for the visibility of the viscometer and the thermometer.

• Timing Device: A stopwatch or stop clock capable of being read up to half a second.

• Viscometer Holder

SAMPLE:

• Heat the sample to a temperature not more than 60°C for tars and pitches and not

more than 90% for bitumen above the corresponding approximate softening point

temperature respectively until it attains pouring consistency.

• Stir it thoroughly and transfer approximately 20 ml in a 30 ml container.

• Local over-heating and entrapped air should be avoided.



TEST PROCEDURE:

• Mount the BS U-tube viscometer in the constant temperature bath keeping tube L

vertical.

• Pour sample through tube N to a point just above filling mark G, allow the sample

to flow freely through capillary R, taking care that the liquid column remains

unbroken until the lower mark H and then arrest its flow by closing the timing tube

with a cork or rubber stopper in tube L.

• Add more liquid, if necessary, to bring the upper meniscus slightly above mark G.

• After allowing the sample to attain bath temperature and any air bubble to rise to

the surface (usually about 20-30 min is required), gently loosen the stopper allowing

the sample to flow until it is approximately at the lower filling mark H and press

back the stopper to arrest flow.

• Remove the excess sample above filling mark G by inserting the special pipette

until its cork rests on top of the tube N and apply gentle suction until air is drawn

through.



• The upper meniscus shall coincide with mark G. Allow the viscometer to remain in

the constant temperature bath for an enough time to ensure that the sample reaches

temperature equilibrium.

• It takes about 20 min at 38°C, 25 min at 100°C and 30 min at 135°C. Remove the

stopper in the tube N and L respectively and allow the sample to flow by gravity.

• Measure to the nearest 0.1 s the time required for the leading edge of the meniscus

to pass from timing mark E to timing mark F.

• If this efflux time is less than 60 s select a viscometer of smaller capillary diameter

and repeat the operation.

• Upon of the test, clean the viscometer thoroughly by several mixing with an

appropriate solvent completely miscible with the sample followed by a completely

volatile solvent.

• Dry the tube by passing slow stream of filtered dry air through the capillary until

the last trace of solvent is removed.

CALCULATION:

• Calculate and report the absolute viscosity to three significant figures, by the

following equation:

o Kinematic viscosity cSt = Ct

Where, C = calibration constant of the viscometer in centistokes per second;

and

t = flow or efflux time, in seconds

• Report always the test temperature along with the results

OBSERVATION:

Grade of Bitumen:

Test Temperature:

Parameter

For Bulb C

Flow Time, Seconds (FT)

Calibration Factor (CF)

Viscosity in cSt (FT x CF)



EXERCISE:

1) Suggest the minimum kinematic viscosity for VG-30 Grade Bitumen. ……………

2) For viscosity graded bitumen the kinematic viscosity is determined at

temperature…………….

3) Is there any need to apply vacuum for determination of kinematic viscosity? Yes / No.





INTRODUCTION TO THIN FILM OVEN TEST-TFOT (ASTM D

1754 or IS:9382)

OBJECTIVE:

• To determine loss on heating of bitumen.

APPARATUS:

• Thin Film Oven

TEST PROCEDURE:

• The thin film oven test (TFOT) is conducted by placing a 50g sample of bitumen in

a cylindrical flat-bottom pan (5.5 inches inside diameter and 3/8 inch deep).

• The bitumen layer in the pan is about 1/8 inch deep. The pan containing the bitumen

sample is transferred to a shelf in a ventilated oven maintained at 160°C (325°F) the

shelf rotates at 5 to 6 revolutions per minute (RPM).

• The sample is kept in the oven for 5 h, and then transferred to a suitable container

for measuring penetration or viscosity of the aged bitumen.

• The test method is described in ASTM D 1754 or IS:9382. The aged bitumen is

usually required to meet specified maximum viscosity ratio at 60°C which is four in

case of IS:73-2013. A loss or gain in weight of the test sample is also measured and

reported.




FLASH AND FIRE POINT TEST (IS:1209-1978)

FLASH POINT – The flash point of a material is the lowest temperature at which the

application of test flame causes the vapours from the material to momentarily catch fire in

the form of a flash under specified conditions of the test.

FIRE POINT – The fire point is the lowest temperature at which the application of test

flame causes the material to ignite and burn at least for 5 seconds under specified conditions

of the test.

OBJECTIVE:

• To determine the temperatures at which bitumen causes flash and fire respectively.

APPARATUS:

• Pensky-Martens Tester consisting of following major parts:

o Cup

o Lid including stirring device, cover proper, shutter and flame exposure

device

o Stove consisting of air bath and top plate

o Thermometer of range – 7oC to 400 oC



TEST PROCEDURE:

• Clean and dry all parts of the cup and its accessories thoroughly before the test is

started. Take particular care to avoid the presence of any solvent used to clean the

apparatus after a previous test.

• Fill the cup with the material to be tested up to the level indicated by the filling mark.

Place the lid on the cup and set the latter in the stove.

• Take care that the locating devices are properly engaged. Insert the thermometer.

• Light and adjust the test-flame so that it is of the size of a bead of 4 mm in diameter.

Apply heat at such a rate that the temperature recorded by the thermometer increases

between 5 to 6oC per minute.

• Turn the stirrer at a rate of approximately 60 revolutions per minute. Apply the test-

flame at each temperature reading which is a multiple of 1°C up to 104°C.

• For the temperature range above 104°C, apply the test-flame at each temperature

reading which is a multiple of 2°C, the first application of the test-flame being made

at a temperature at least 17°C below the actual flash point.

• Apply the test-flame by operating the device controlling the shutter and test-flame

burner so that the flam e is lowered in 0.5 seconds, left in its lowered position for one

second, and quickly raised to its high position.

• The test-flame will neither be larger than stipulated nor will it be applied more

frequently than specified as the surface layer is liable to be superheated.

• The bluish halo that sometimes surrounds the test-flame shall not be confused with

the true flash.

• Discontinue the stirring during the application of the test-flame.

TEST PROCEDURE:

• Clean and dry all parts of the cup and its accessories thoroughly before the test is

started. Take particular

OBSERVATION:

Property Test I Test II Mean Value

Flash point, oC

Fire point, oC

CONCLUSION:




OTHER TESTS


BITUMEN SPECIFIC GRAVITY TEST (IS: 1202-1978)

The ratio of mass of a given volume of the substance to the mass of an equal volume of

water, the temperature of both being specified. The specific gravity of bitumen is

determined at 25oC temperature.

OBJECTIVE:

• To determine the specific gravity of bitumen.

APPARATUS:

• Specific gravity bottle of 50 ml of wide mouthed capillary type with a neck of 25 mm

diameter shall be used.

• The stopper shall be provided with a bore 1.0 to 2.0 mm in diameter centrally located

in reference to the vertical axis. The top surface shall be smooth and lower surface

shall be concave to allow air to escape through the bore.

• Constant Temperature Bath

• Thermometer of range 0 to 50oC

TEST PROCEDURE:

• Clean, dry and weigh the specific gravity bottle together with the stopper (a).

• Fill it with freshly boiled and cooled distilled water and insert the stopper firmly.

• Keep the bottle up to its neck for not less than half an hour in a beaker of distilled

water maintained at a temperature of 27.0 ± 0.1 o C or any other temperature at which

specific gravity is to be determined; wipe all surplus moisture from the surface with

a clean, dry cloth and weigh again (b).

• After weighing the bottle and water together (b) the bottle shall be dried again.

• In the case of solids and semisolids, bring a small amount of the material to a fluid

condition by gentle application of heat, care being taken to prevent loss by

evaporation.

• When the material is sufficiently fluid, pour a quantity into the clean, dry specific

gravity to fill at least half. Slightly warm the bottle before filling.

• Keep the material away from touching the sides above the final level of the bottle and

avoid the inclusion of air bubbles.

• The use of a small funnel will prevent contamination of the neck of the bottle.

• To permit escape of entangled air bubbles allow the partly filled bottle to stand for

half an hour at a temperature between 60 - 70°C, then cool to the specified

temperature and weigh with the stopper (c).



• Fill the specific gravity bottle containing the asphalt with freshly boiled distilled water

placing the stopper loosely in the specific gravity bottle. Do not allow any air bubble to

remain in the specific gravity bottle.

• Place the specific gravity bottle in the water bath and press the stopper firmly in place.

Allow the specific gravity bottle to remain in the water bath for a period of not less than

30 minutes.

• Remove the specific gravity bottle from the water bath, wipe all surplus moisture from

the surface with a clean dry cloth and weigh it along with the stopper (d).

OBSERVATION:

Weight of Specific Gravity Bottle, a = ……………… g

Weight of Specific Gravity Bottle filled with distilled water, b = ……………… g

Weight of Specific Gravity Bottle about half filled with the material, c = ……………… g

Weight of Specific Gravity Bottle about half filled with the material and the rest with distilled

water, d = ……………… g

Specific Gravity = 𝑐−𝑎

(𝑏−𝑎)−(𝑑−𝑐) =

CONCLUSION:

EXERCISE:

1) What is the range of specific gravity of bitumen?





BITUMEN DUCTILITY TEST (IS:1208 - 1978)

The ductility of a bituminous material is measured by the distance in centimeters to which

it will elongate before breaking when a briquette specimen of the material are pulled apart

at a specified speed and at a specified temperature.

OBJECTIVE:

• To determine the ductility of bitumen.

APPARATUS:

• Mould having dimensions as shown in figure. The ends a and a’ are sides of mould

and b and b’ are clips of mould.

• The dimensions of mould are such that when properly assembled, it will form a

briquette specimen having following dimensions:

o Total length: 75 ± 0.5 mm

o Distance between clips: 30 ± 0.3 mm

o Width at mouth of clip: 20 ± 0.2 mm

o Width at minimum cross section: 10 ± 0.1 mm

o Thickness throughout: 10 ± 0.1 mm

• Water Bath preferably with a thermostat maintained within ± 0.1oC of the specified

test temperature.

• Testing Machine for pulling the briquette of bituminous material apart horizontally

with minimum vibrations at a speed of 50 mm per minute and it shall have suitable

arrangement for stirring the water for attaining uniformity in temperature.



SAMPLE:

• Completely melt the bituminous material to be tested to a temperature of 75 to 100°C

above the approximately softening point until it becomes thoroughly fluid.

• Assemble the mould on a brass plate and in order to prevent the material under test from

sticking, thoroughly coat the surface of the plate and interior surfaces of the sides of the

mould with a mixture of equal parts of glycerine and dextrine.

• In filling, pour the material in a thin stream back and forth from end to end of the mould

until it is more than level full.

• Leave it to cool at the room temperature for 30 to 40 min, and then place in a water bath

maintained at the specified temperature for 30 min after which cut off the excess bitumen

by means of a hot, straight-edged putty knife or spatula so that the mould shall be just

level full.

TEST PROCEDURE:

• Unless otherwise specified, the test shall be conducted at a temperature of 25.0 ± 0.5°C

and at a rate of pull of 50.0 ± 2.5 mm/mm.

• Place the brass plate and mould with briquette specimen, in the water bath and keep at

the specified temperature for about 85 to 95 minutes.

• Then remove the briquette from the plate, detach the side pieces, and test the briquette

immediately.

• Attach the rings at each end of the clips to the pins or hooks in the resting machine and

pull the two clips apart horizontally at a uniform speed as specified until the briquette

ruptures.

• Measure the distance in centimetres through which the clips have been pulled to produce

rupture. While the test is being made, make sure that the water in the tank of the testing

machine covers the specimen both above and below it by at least 25 mm and is

maintained continuously within ± 0.5°C of the specified temperature.

• A normal test is one in which the material between the two clips pulls out to a point or

to a thread and rupture occurs where the cross-sectional area is a minimum.

• Report the average of three normal tests as the ductility of the sample.

• If the bituminous material meets the surface of the water or the bottom of the bath, the

test shall not be considered normal.

• Adjust the specific gravity of the water in the bath by the addition of either methyl

alcohol or sodium chloride so that the bituminous material does not either come to the

surface of the water or touch the bottom of the bath at any time during the test.



OBSERVATION:

Grade of Bitumen:

Pouring Temperature:

Period of Air Cooling:

Period up to which Sample placed in water bath:



Rate of Pulling:

Briquette

No.

Distance at which Bitumen thread

breaks

Mean Value

1

2

3

EXERCISE:

1) The temperature at which ductility test is carried out is …………. oC.

2) The rate of pulling briquettes during ductility test is …………… mm/min.

3) What is the minimum ductility value for VG 30 Grade Bitumen?

4) Draw a neat sketch of mould used for bitumen ductility test.




SECTION-D

TEST OF BITUMINOUS MIX


18 % Bitumen content in paving mixture IRC: SP: 11 - 1988

19 Stripping value of road aggregate IS: 6241-1971

20 Marshal stability test-determination of

optimum bitumen content MS-2 7th Edition




QUANTITATIVE EXTRACTION OF BITUMEN FROM BITUMEN

PAVING MIXTURE (IRC: SP: 11 - 1988)

OBJECTIVE:

• To determine the percentage amount of bitumen in the paving mixture.

APPARATUS:

• Extraction Apparatus: consisting of a rotating machine in which the bowl may be

revolved at controlled variable speeds up to 3600 rpm The apparatus shall be

provided with a shell for catching the solvent thrown from the bowl and a drain for

removing the solvent. The apparatus preferably shall be provided with explosion

proof features and installed under a hood to provide ventilation.

• Benzene

• Filter Rings

• Oven: capable of being maintained at 150oC

• Balance: of 5000 g capacity, sensitivity to 0.1 g

• Graduate: 2000 ml capacity

SAMPLE:

• A representative sample about 500 gm is exactly weighed and placed in the bowl of

the extraction apparatus and covered with commercial grade of benzene.

• Enough time (not more than 1 hour) is allowed for the solvent to disintegrate the

sample before running the centrifuge.



TEST PROCEDURE:

• The filter ring of the extractor is dried, weighed and then fitted around the edge of

the bowl. The cover of the bowl is clamped tightly. A beaker is placed under to

collect the extract.

• The machine is revolved slowly and then gradually, the speed is increased to a

maximum of 3600 RPM. The speed is maintained till the solvent ceases to flow

from the drain.

• The machine is allowed to stop and 200ml of the benzene is added and above

procedure is repeated.

• Several 200 ml solvent additions (not less than three) are used till the extract is clear

and not darker than a light straw colour.

• The filter ring from the bowl is removed, dried in air and then in oven to a constant

temperature at 115oC, and weighed.

• The fine materials that have passed through the filter paper are collected back from

the extract preferable by centrifuging.

• The material is washed and dried to constant weight as before.

OBSERVATIONS:

Weight of Sample, W1 =

Weight of Sample after extraction, W2 =

Weight of fine material recovered from the extract, W3 =

Increase in weight of filter ring, W4 =

Percentage Binder in Mix = 𝑾𝟏−(𝑾𝟐+ 𝑾𝟑)+ 𝑾𝟒

𝑾𝟏

CONCLUSION:





STRIPPING VALUE OF ROAD AGGREGATES (IS: 6241-1971)

OBJECTIVE:

• To determine the adhesion property of aggregate with different types of bituminous

binders so that suitability of aggregates could be ascertained.

APPARATUS:

• IS Sieve of sizes 20.0 mm and 12.0 mm

• Water Bath

• Stove

• 500 ml Beaker

TEST PROCEDURE:

• Take 200 grams of dry and clean aggregates passing 20 mm and retained on 12.5 mm

sieves and heat up to 150 C.

• Take five percent by weight of bitumen binder and heat up to 160 C.

• Mix the aggregates and the binder till they are completely coated and transfer the

mixture in to a 500 ml beaker and allow to cool at room temperature for about 2

hours.

• Add distilled water to immerse the coated aggregates.

• Cover the beaker and keep in a water bath maintained at 40 C taking care that the

level of water in the water bath is at least half the height of the beaker.

• After 24 hours take the beaker out, cool at room temperature and estimate the extent

of stripping visually while the specimen is still under the water.

OBSERVATION:

Test

No.

Uncovered area observed visually/Total area of the

aggregates Mean

1

2

3

CONCLUSION:





MARSHALL MIX DESIGN (MS-2 7th Edition)

OBJECTIVE:

• To determine the optimum binder content for a paving mixture

APPARATUS:

• Marshall Stability testing machine

• Cylindrical Mould internal diameter 100 mm and height 75 mm

• Compaction Hammer of 4500 g and free fall of 4570 mm

• Compaction Pedestal

• IS Sieves

SAMPLE:

• Before developing the Marshall mix design, representative samples of paving

bitumen and aggregates proposed to be used on the project should be collected.

• These samples must be tested and must meet all specification criteria as laid down in

MoRT&H specifications.



TEST PROCEDURE:

Preparation of Compacted Specimens

• Decide the type of mix to be prepared viz., Bituminous Macadam, Dense Bituminous

Macadam, Bituminous Concrete, Semi-Dense Bituminous Concrete etc….

• Collect different sizes of aggregate and mix them well in adequate proportion to

achieve desired gradation of the above stated types of mixes. (For this refer

Experiment No. 6)

• Prepare a sample of 1200 g mixed aggregates as discussed in previous point.

• Heat the prepared aggregate mixture.

• Also heat the sufficient amount of bitumen. Three compacted specimens each should

be prepared at 5 different bitumen contents. Bitumen contents are usually selected in

0.5% increments with at least two bitumen contents above estimated “optimum” and

at least two below “optimum”. Refer to MoRT&H guidelines for approximate

“optimum” bitumen content or the estimate of optimum bitumen content can be based

on experience.

• The temperature for various operations is given in table below for different bitumen

grades:

Bitumen

Viscosity

Grade

Bitumen

Temperature

Aggregate

Temperature

Mixed

Material

Temperature

Laying

Temperature

Rolling

Temperature

VG 40 160-170 160-175 160-170 150 Min. 100 Min.

VG 30 150-165 150-170 150-165 140 Min. 90 Min.

VG 20 145-165 145-170 145-165 135 Min. 85 Min.

VG 10 140-160 140-165 140-160 130 Min. 80 Min.

• As the aggregates and the bitumen reaches sufficient temperature as mentioned in the

table above thoroughly mix them keeping in view the Mixed Material Temperature

until all the aggregate is coated.

• Mixing can be by hand, but a mechanical mixer is preferred. When mixing is done

by hand, place the mixing bowl on a hot plate to ensure mix does not cool while

mixing.

• Check temperature of freshly mixed material; if it is above the compaction

temperature, allow it to cool to compaction temperature; if it is below compaction

temperature, discard the material and make a new mix.

• Place a paper disc into an assembled, preheated Marshall mould and pour in loose

bitumen mix. Check the temperature again. Spade the mixture with a heated spatula.

• Remove the collar and mound material inside mould so that middle is slightly higher

than edges.

• Attach mould and base plate to pedestal.



• Place preheated hammer in the mould and apply appropriate number of blows

(usually 75 blows in India) to top side of specimen.

• Remove the mould from base plate. Place a paper disc on top of specimen and invert

the mould upside down. Replace the mould collar and attach mould and base plate to

the pedestal. Place hammer on the mould and apply same number of blows to bottom

as were applied to the top.

• Remove filter papers from top and bottom of specimens. Cool specimens at room

temperature for 24 Hours and then extrude from mould.

• Place identification marks on each specimen.

• Allow specimens to sit at room temperature overnight for further testing.

• Determine the bulk specific gravity (Gmb) of each specimen by weighing in air.

Submerge samples in water and allow saturating prior to getting submerged weight

in saturate surface dry (SSD) condition.

• Remove sample and weigh in air in SSD condition.

• Measure the maximum specific gravity (Gmm) of the loose asphalt mix samples in

accordance with ASTM D 2041.

Determination of Marshall Stability and Flow

• Heat the water bath to 60oC and place specimens to be tested in the bath for at

least 30 min but not more than 40 min. Place specimens in the bath in staggered

manner to ensure that all specimens have been heated for the same length of time

before testing.

• After heating for the required amount of time, remove a specimen from the water

bath, pat with towel to remove excess water, and quickly place in the Marshall

testing head.

• Bring loading ram into contact with testing head. Zero the flow gauge and

loading gauge.

• Apply load at 50 mm/min until maximum load is reached.

• When load just begins to decrease, remove the flow meter, stop ram movement,

and record stability (maximum load) in kN and flow in 0.25 mm.

• Testing should be completed within 1 min from the time the specimen is remove

from the hot water bath.

• It is possible while making the specimen that the thickness slightly varies from

the standard specification of 63.5 mm. Therefore, measured stability values need

to be corrected to those which would have been obtained if the specimens had

been exactly 63.5 mm. This is done by multiplying each measured stability value

by an appropriated correlation factors as given in Table below:



Volume of

specimen

(cm3)

Thickness of

specimen(mm)

Correction

factor

457 - 470 57.1 1.19

471 - 482 68.7 1.14

483 - 495 60.3 1.09

496 - 508 61.9 1.04

509 - 522 63.5 1.00

523 - 535 65.1 0.96

536 - 546 66.7 0.93

547 - 559 68.3 0.89

560 - 573 69.9 0.86

Calculation of mix volumetrics

• For each specimen, use bulk specific gravity (Gmb) and the maximum specific

gravity (Gmm) to calculate percentage air voids (Va) as follows:

o Va = 100 𝑋 𝐺𝑚𝑚− 𝐺𝑚𝑏

𝐺𝑚𝑚

• Calculate the voids in mineral aggregate for each specimen using bulk specific

gravity of aggregate (Gsb) and the bulk specific gravity of compacted mix (Gmb),

and the percentage of aggregate by weight of total mix (Ps) as follows:

o Gsb = 𝑃1+ 𝑃2+ 𝑃3+ ….𝑃𝑁

𝑃1𝐺1

+𝑃2𝐺2

+𝑃3𝐺3

+....𝑃𝑁𝐺𝑁

Where P1, P2, P3…..PN = Proportion of different sizes of aggregates

G1, G2, G3…..GN = Specific Gravity of different sizes of

aggregates

o VMA = 100 − 𝐺𝑚𝑏 𝑃𝑠

𝐺𝑠𝑏

• Calculate the voids filled with bitumen (VFB) for each marshall specimen using

the air voids and VMA as follows:

o VFB = 100(𝑉𝑀𝐴− 𝑉𝑎)

𝑉𝑀𝐴

Preparation of Graphical Plots with Bitumen Content on X-Axis

• All the volumetric properties, stability and flow values of each specimen (3 Nos.)

having same binder content is averaged and graphs are plotted for 5 different

binder content samples (2 binder contents below optimum, 2 binder contents

above optimum and 1 optimum binder content).



• Plot the graphs

o Bitumen content vs bulk specific gravity (or density or unit weight)

o Bitumen content vs Marshall stability

o Bitumen content vs flow

o Bitumen content vs air voids

o Bitumen content vs VMA

o Bitumen content vs VFB or VFA

Determination of Optimum Binder Content

• Optimum binder content is amount of bitumen corresponding to air

voids of 4%.



OBSERVATION:

• Gradation and Blending of Aggregates

IS

Sieve

Size

in

mm

% Weight

Passing of

………mm

Aggregates

% Weight

Passing of

………mm

Aggregates

% Weight

Passing of

………mm

Aggregates

% Weight

Passing of

………mm

Aggregates Obtained

Gradation

Desired


(%)

……………..

Proportion

(%)

……………..

Proportion

(%)

……………..

Proportion

(%)

……………..

• Specific Gravity of Aggregate Type-1 =




• Bulk Specific Gravity of Total Aggregate = Gsb = 𝑃1+ 𝑃2+ 𝑃3+ ….𝑃𝑁𝑃1𝐺1

+𝑃2𝐺2

+𝑃3𝐺3

+⋯.𝑃𝑁𝐺𝑁

• Bitumen percentage by weight of aggregate =

• Compacted Mix Density

Sample

No.

Weight in

Air (g)

Weight in

Water (g)

SSD

Weight

(g)

Volume,

III - II

(cc)

Density,

I/IV

(g/cc)

I II III IV V



• Theoretical Maximum Specific Gravity, Gmm =

• Voids in Mineral Aggregates, VMA = 100 − 𝐺𝑚𝑏 𝑃𝑠

𝐺𝑠𝑏 =

1)

2)

3)

• Air Voids, Va = 100 𝑋 𝐺𝑚𝑚− 𝐺𝑚𝑏

𝐺𝑚𝑚

1)

2)

3)

• Voids filled by Bitumen or Asphalt, VFB or VFA = 100(𝑉𝑀𝐴− 𝑉𝑎)

𝑉𝑀𝐴 =

1)

2)

3)

• Marshall Stability & Flow

Sample

No.

Sample Dimensions

(mm) Correction

Factor

Marshall

Stability

Value

(kN)

Corrected

Marshall

Stability

(kN)

Flow

(mm) Diameter Thickness



Comparison table of bitumen test

Specification Name of test

Penetration Ductility Viscosity

Softening point Flash & fire

point Specific

gravity Absolute Kinematic

Measure Hardness

1/10 th of

penetration

Affecting on

bitumen with Resistant to

flow Resistant to

flow

Temperature at

which bitumen

soften

Hazardous

temp. Quality

Test temp. 25 C° 27 C° 60 C° 135 C° - - 27 C°

Instrument Penetrometer Ductility

machine

Viscosity bath +

Canon manning

tube

Viscosity bath +

Canon manning

tube

Ring & ball

apparatus Pensky

marten Specific gravity

bottle

Brief

specification

Needle 1

sq.mm. 100

gm wt.

Penetration

for 5 sec

Briquette area-1

cm2

Pulling Rate -50

mm/min rate

Canon manning tube

9.5 mm dia.

2.5g ± 0.05gm

wt. of ball

Start heating

from 5°C

- -



SECTION-E

DESIGN OF CONCRETE MIX FOR PAVEMENT

EXPERIMENT NO: 21 DATE:

DESIGN OF CONCRETE MIX FOR PQC (IRC:44-2008)

EXAMPLE – 1 EXAMPLE ON CONCRETE MIX PROPORTIONING

STIPULATIONS FOR PROPORTIONING

(a) Grade designation M40

(b) Type of cement OPC 43 grade conforming to IS:8112

(c) Maximum nominal size of aggregate 20 mm

(d) Minimum cement content 325 kg/m3

(e) Maximum water-cement ratio 0.50

(f) Workability 20 ± 5 mm (slump)

(g) Degree of supervision Good

(h) Type of aggregate Crushed angular aggregate

(i) Maximum cement content 425 kg/m3

g) Chemical admixture type Superplasticizer

TEST DATA FOR MATERIALS

(a) Cement used OPC 43 grade conforming to IS:8112

(b) Specific gravity

Cement

Coarse aggregate

Fine aggregate

3.15

2.74

2.62

(c)Water absorption

(1) Coarse aggregate

(2) Fine aggregate

0.5 per cent

1.0 per cent

(d)Free (surface) moisture

(1) Coarse aggregate

(2) Fine aggregate

Nil (absorbed moisture also nil)

Nil



(e) Sieve

analysis

(1)

Coarse

aggregate

IS

Sieve

sizes

mm

Analysis of Coarse

Aggregate

Fraction, % Passing

Percentage Passing of

Different Fractions

Percentage

passing for

graded

aggregate

as per Table

1

I

20 to 10

mm

10 mm

down

60% 40% Combined

100%

20 100.0 100.0 60.00 40.00 100.00 95-100

10 2.80 78.30 1.68 31.30 32.98 25-55

4.75 Nil 8.70 3.48 3.48 0-10

DESIGN COMPRESSIVE STRENGTH FOR MIX PROPORTIONING

f 'ck= fck+ 1.65 x s

Where, f 'ck = target average compressive strength, N/mm2 at 28 days.

fck = characteristic compressive strength, N/mm2 at 28 days.

s = standard deviation, N/mm2

Assumed Standard Deviation (IRC:44-2008)

Sr. No. Grade of Concrete Assumed Standard Deviation (N/mm2)

1 M25 4.0

2 M30

5.0

3 M35

4 M40

5 M45

6 M50

7 M55

8 M60

From above table, Standard Deviation = 5.0 N/mm2

Therefore, design compressive strength = 40 + 1.65 x 5.0 = 48.25 N/mm2

Design flexural strength using IS: 456 relationships = 4.86 N/mm2



SELECTION OFWATER-CEMENT RATIO

Preliminary Selection of Water-Cement Ratio for the Given Grade (IRC:44-2008)

Sr. No. Grade of Concrete Approximate Water/cement ratio

1 M25 0.50

2 M30 0.45

3 M35 0.42

4 M40 0.38

5 M50 0.34

6 M60 0.28

From above table preliminary water-cement ratio = 0.38, 0.38 < 0.50, hence OK.

SELECTION OFWATER CONTENT

Approximate Water Content per Cubic Meter of Concrete for Nominal Maximum

Size of Aggregate (without Plasticizer/Superplasticizer) (IRC:44-2008)

Nominal Maximum Size of Aggregate

(mm) Suggestive water content (kg)

20 208

10 186

40 165

From above table, water content for 20 mm aggregate = 186 kg/m3 at W/C = 0.5

As super plasticizer is proposed to be used, the water content can be reduced maximum

upto30%. For the purpose of present trial exercise, a reduction of water content of 15% has

been assumed by adjusting suitably the doses of the super plasticizer. The designer can use

this reduction as per his requirement of the availability of the grade of cement and quality

of super plasticizer. With 15% reduction in water content at water-cement ratio of0.38, the

reduced water content equals to186 x 0.85=158.1 kg, say 158 kg.

CALCULATION OF CEMENT CONTENT

Water-cement ratio = 0.38

Water content = 158 kg/m3

Cement content = 158/0.38 = 415.80 kg/rn3, say 416.0 kg/m3

Check for minimum and maximum cement content as per IRC: 15

Minimum cement content as per IRC: 15,325 kg/m3<416 kg/m3 Hence, OK

Maximum cement content as per IRC: 15,425 kg/m3>416 kg/m3 Hence, OK



PROPORTION OF VOLUME OF COARSE AGGREGATE AND FINE

AGGREGATE

Volume of Coarse Aggregate Per Unit Volume of Total Aggregate for Different

Zones of Fine Aggregate as per IS: 383 (IRC:44-2008)

Nominal

Maximum

Size of Aggregate

(mm)

Volume of Coarse Aggregate Per Unit Volume of Total

Aggregate for Different Zones of Fine Aggregate

Zone IV Zone III Zone II Zone I

10 0.50 0.48 0.46 0.44

20 0.66 0.64 0.62 0.60

40 0.75 0.73 0.71 0.69

From above table, volume of coarse aggregate corresponding to 20 mm size aggregate and

fine aggregate grading Zone II = 0.62 per unit volume of total aggregate. This is valid for

water-cement ratio of 0.50. As water-cement ratio is 0.38, the ratio is taken as 0.64 to reduce

sand content.

Volume of fine aggregate content = 1 - 0.64 = 0.36 per unit volume of total aggregate

MIX CALCULATIONS

(a) Volume of concrete = 1 m3

(b)Volume of cement = (Mass of cement/Specific gravity of cement)

x (1/1000)

= (416/3.15) x (1/1000)

= 0.132 m3

(c)Volume of water = (Mass of water/Specific gravity of water) x

(l/100)

= (158/1) x (1/1000)

= 0.158 m3

(d)Volume of chemical

admixture (super plasticizer)

[@ 0.6% by mass of cementations material]

= (Mass admixture/Specific gravity of

admixture) x (1/1000)

= (2.50/1.2) x (111000)

=0.002 m3

(e)Volume of all in aggregate = {a - (b + c + d)}

= {1-(0.132+0.158+0.002)}

= 0.708 m3

(f) Mass of coarse aggregate = (e) x 0.64 x Specific gravity of coarse

aggregate x 1000

= 0.708 x 0.64 x 2.74 x 1000

= 1241.5 Say 1242 kg/m3

(g) Mass of fine aggregate =(e) x 0.36 x Specific gravity of fine aggregate

x 1000

= 0.708 x 0.36 x 2.62 x 1000

= 667.8 Say 668 kg/m3



MIX PROPORTIONS FOR TRIAL NUMBER 1 BASED ON AGGREGATE IN SSD

CONDITION

Cement = 416 kg/m3

Water = 158 kg/m3

Fine Aggregate = 668 kg/m3

Coarse Aggregate = 1242 kg/m3

Chemical Admixture = 2.50 kg/m3


MIX PROPORTIONS FOR TRIAL NUMBER 1 BASED ON AGGREGATE IN

DRY CONDITION

Cement = 416 kg/m3

Water =158 + 6.68 + 6.21 =170.9 kg/ m3

Chemical Admixture = 2.50 kg/ m3

Fine Aggregate = 661.3 kg (668 - 1 % of 668)

Coarse Aggregate = 1235.8 kg (1242 - 0.5% of 1242)

The slump shall be measured, and the water content and dosage of admixture shall be

adjusted for achieving the required slump based on trial, if required. The mix proportions

shall be reworked for the actual water content and checked for durability requirements.

Two more trials having variation of ±10percentofwater-cementratio in C-10 shall be

carried out and a graph between three water-cement ratios and their corresponding

strengths shall be plotted to work out the mix proportions for the given target strength for

field trials. However, minimum and maximum cement content requirements should be

met.

Adjustment due to higher slump requirements for use of RMC can be made as follows:

Based on initial trials, it has been established that for expected 1-hour transit time initial

slump requirement is 100 mm for 20 mm slump at the time of placement.

Based on trials, dosage of admixture may be increased from 0.6 per cent to 1.0 per cent

by mass of cement to achieve required workability (accordingly all other calculations

can be modified).



IN CASE IT IS PROPOSED TO USE FLY ASH IN THE CONCRETE

CALCULATION OF CEMENT AND FLYASH CONTENTS


Cement content 158/0.38 = 416 kg/m3

Now, to proportion a mix containing fly ash the following steps are suggested:

(i) Decide percentage of fly ash to be used based on project requirement and quality of

materials.

(ii) *Increase the cementitious material content by 10% of total cementitious material

content of control mix calculated as above, to account for fly ash reactivity.

Cementitious material content = 416 x 1.10 = 457.6 kg/m3, say 458 kg/m3

* In certain situations, increase in cementitious material content may be warranted. The

decision on increase in cementitious material and its percentage may be based on

experience and trial. This illustrative example is with increase of 10 per cent cementitious

material content.

Water Content = 158 kg/m3

So, water-cementitious material ratio = 158/458 = 0.345

Fly ash @ 20 per cent of total cementitious content = 458 x 20%

= 91.6 kg/m3

Say = 92 kg/m3

Cement (OPC) = 458 - 92 = 366 kg/m3

Check for maximum cement content

Maximum cement (OPC) content as per IRC: 15,425 kg/m3> 366 kg/m3

Hence, OK

Check for minimum cementitious content, 325kg/m3<458kg/m

3

(366kg/m3

OPC + 92

kg/m3 fly ash) Hence, OK



PROPORTION OF VOLUME OF COARSE AGGREGATE AND FINE

AGGREGATE CONTENT

Volume of coarse aggregate corresponding to 20 mm size aggregate and fine aggregate

Zone II= 0.62 per unit volume of total aggregate. This is valid for water-cement ratio of

0.50. As water-cement ratio is 0.345, the ratio is taken as 0.65 to reduce sand content.

Volume of fine aggregate content =1-0.65=0.35 per unit volume of total aggregate

MIX CALCULATIONS

(a) Volume of concrete = 1m3

(b) Volume of cement = (Mass of cement/Specific gravity of cement) x

(1/1000)

= (366/3.15) x 1/1000

=0.116 m3

(c) Volume of fly ash = (Mass of fly ash/Specific gravity of fly ash)

x1/1000

= (92/2.2) x 1/1000

=0.042 m3

(d) Volume of water = (Mass of water/Specific gravity of water) x

1/1000

= (158/1) x 1/1000

= 0.158 m3

(e) Volume of chemical

[@ 0.8% by Mass of

cementitious material]

= (Mass of chemical admixture/Specific gravity

of admixture) x (l/1000)

= (3.66/1.2) x 1/1000

= 0.003 m3

(f) Volume of all-in aggregate = {a- (b + c + d + e)}

= {1- (0.116 + 0.042 + 0.158 + 0.003)

= 0.681 m3

(g) Mass of coarse aggregate = (f) x volume of coarse aggregate x

Specific gravity of coarse aggregate x 1000

= 0.681 x 0.65 x 2.74 x 1000

= 1212.9 Say 1213 kg/m3

(h) Mass of fine aggregate = (f) x volume of fine aggregate x Specific

gravity of fine aggregate x 1000

= 0.681 x 0.35 x 2.62 x 1000

= 624.5 Say 625 kg/m3



MIX PROPORTIONS FOR TRIAL NUMBER 1 ON AGGREGATE IN

(SATURATED SURFACE DRY) SSD CONDITION

Cement = 366 kg/m3

Fly Ash = 92 kg/ m3

Water = 158 kg/ m3

Fine Aggregate = 625 kg/ m3

Coarse Aggregate = 1213 kg/ m3

Chemical Admixture = 3.66 kg/ m3

Water-cementitious material ratio = 0.345

MIX PROPORTIONS FOR TRIAL NUMBER 1 ON AGGREGATE IN DRY

CONDITION

Cement = 366 kg/m3

Fly Ash = 92 kg/ m3

Water = 158 + 6.3 + 6.1 = 170.4 kg

Fine Aggregate = 618.7 kg/m3 (625 – 1% of 625)

Coarse Aggregate =1206.9 kg/m3 (1213 - 0.5% of 1213)

Chemical Admixture = 3.66 kg/m3

Water-cementitious material ratio = 0.345

All other steps will remain same.



SECTION-F

A STUDY ON TRAFFIC PARAMETERS

SECTION-F: A STUDY ON TRAFFIC PARAMETERS

22 Spot Speed Study

23 Traffic Volume Study

24 Accident Study




SPOT SPEED STUDY

Spot Speed is the instantaneous speed of a vehicle at any specific location. Spot speed is a

traffic parameter which is measure over a short distance. Spot speed studies are used to

determine the speed distribution of a traffic stream at specific location. The data gathered

in spot speed studies are used to determine vehicle speed percentiles, which are useful in

making many speed-related decisions.

OBJECTIVE:

• To determine design speed, safe speed or maximum speed, minimum speed and

modal speed, space mean speed.

APPARATUS:

• Measuring tape of 30 m.

• Stopwatch

PROCEDURE:

• Mark two lines on the road in transverse direction (along the width of road) spaced

at 60 m from each other.

• Start the stopwatch when the vehicle arrives at one line and stop it when vehicle

reaches another line.

• Record the time in seconds.

• Find speed in kmph using the formula

• Speed in kmph = ( Distance / Time ) x 3.6

• After finding speed of each vehicle, count the number of vehicles falling under

different ranges of speed.

• For e.g., count number of vehicles travelling at speed in between 1 and 10 kmph

count number of vehicles travelling at speed in between 11 and 20 kmph

count number of vehicles travelling at speed in between 21 and 30 kmph.

.

.

.

.

.

.

count number of vehicles travelling at speed in between 91 and 100 kmph

• Calculate the percentage of number of vehicles falling under different ranges of speed

and represent the data as “PERCENTAGE FREQUENCY”



• Calculate the cumulative percentage of numbers of vehicles falling under different

ranges of speed represent the data as “CUMULATIVE PERCENTAGE

FREQUENCY”

• Plot the following graphs.

• Percentage Frequency (Y-Axis) vs Mid value of speed ranges (X-Axis)

i. The peak point of this graph is Modal Speed

• Cumulative Percentage Frequency (Y-Axis) vs Mid value of speed ranges (X-

Axis)

i. The speed corresponding to 98th Percentile is Design Speed.

ii. The speed corresponding to 85th Percentile is Safe or Maximum Speed

iii. The speed corresponding to 15th Percentile is Minimum Speed

• Space mean speed is calculated by following formula:

• Space mean speed = 𝑁

1

𝑆1+

1

𝑆2+

1

𝑆3+

1

𝑆4………..

1

𝑆𝑁

Where, N = Number of vehicles

S = Speed of each vehicle

OBSERVATION:

Class of Road:

Width of Road:

No. of lanes on the road:

Type of traffic: One Way / Two Way

Median Provided (For two way traffic) : YES / NO



Sr

No.

TIME TAKEN TO COVER DISTANCE

2W 3W 4W BUS LCV HCV BICYCLE

Time Speed Time Speed Time Speed Time Speed Time Speed Time Speed Time Speed

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

NAME OF ENUMERATOR: SIGNATURE:



Speed

Range

kmph

Mid Value of Speed

Range, kmph Frequency

Frequency

(%)

Cumulative %

Frequency

1 – 10 5.5

11 – 20 15.5

21 – 30 25.5

31 – 40 35.5

41 – 50 45.5

51 – 60 55.5

61 – 70 65.5

71 – 80 75.5

81 – 90 85.5

91 – 100 95.5

Modal Speed, kmph: ………………………………….

Design Speed, kmph: …………………………………

Safe or Maximum Speed: ……………………………..

Minimum Speed: ……………………………………..





TRAFFIC VOLUME STUDY

Traffic volume (Flow) is variable. It is of great significance to the traffic engineer. Traffic

volume study is essentially a counting process involving the quantity of movement per unit

time at a specified location. The counting process generally includes composite group of

different types of the vehicles (both slow and fast). The selected time periods in hours, days,

weeks, months or year depend upon the purpose of the study and the required degree of

accuracy.

OBJECTIVE:

• To determine variation in traffic flow, vehicular composition and passenger car unit

APPARATUS:

• Measuring tape of 30 m.

• Watch

PROCEDURE:

• Mark a line on the road in transverse direction (along the width of road).

• Count the number of vehicles of different categories at each 5 minutes interval and

record the data in the sheet.

• Plot a graph showing variation in traffic with Time on X-Axis and total number of

vehicles at each 5 minutes interval on Y-Axis.

• Find the percentage number of each category of vehicle for the whole survey period.

• Find the static passenger car unit as per IRC: 106-1990.

OBSERVATION:

TIME 2W 3W 4W BUS LCV HCV Bicycle TOTAL



TIME 2W 3W 4W BUS LCV HCV Bicycle TOTAL

TOTAL

Vehicle

Type

% Composition in

Traffic Stream

Passenger Car Unit

as Per IRC: 106-1991

2W

3W

4W

Bus

LCV

HCV

Bicycle

QUESTION: Define Traffic volume and Traffic Density

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………





TRAFFIC ACCIDENT STUDY

The problem of accident is very acute in road transportation. Traffic accidents may involve

property damages, personal injuries and deaths. One of the main objectives of traffic

engineering is to provide safe traffic movements.

OBJECTIVES:

• To study the causes of accidents and to suggest corrective treatment at potential

locations.

• To evaluate existing design, regulation and control measures.

• To support proposed changes in design, regulation and control, measures in the

selected zone.

• To carry out ‘before and after studies’ after implementing changes and to

demonstrate the improvement in the accident problem.

• To make computations of financial loss due to accidents.

• To provide economic justification for the improvement measures suggested by the

traffic engineer.

ACCIDENT STUDIES & RECORDS:

• The various steps involved in traffic accident studies are (i) collection of accident

data (ii) preparation of accident reports (iii) preparation of location file (iv)

preparation of diagrams showing type of collision (v) application of the above

records for suggesting measures to prevent similar accidents at the same location.

COLLISION DIAGRAM:

• This diagram depicts the details of the accident location (not to the scale) and show

the approximate path of the vehicles and pedestrians involved in the accident and

other objects with which the vehicles have collided.



CONDITION DIAGRAM:

• A condition diagram is a drawing of the accident location drawn to scale, showing

all the important physical features of the road and adjoining area.



SECTION-G

HIGHWAY GEOMETRIC DESIGN (IRC: 73-1980 & IRC: 86-1983)



HIGHWAY GEOMETRIC DESIGN

HIGHWAY GEOMETRIC DESIGN (IRC:73-1980 & IRC:86-1983)

Geometric Design of a highway deals with the dimensions and layout of visible features of

the highway such as horizontal and vertical alignments, sight distance and intersections. The

geometrics of highway should be designed to provide efficiency in traffic operations with

maximum safety at reasonable cost.

Geometric Design of highways deals with following elements:

• Cross section elements

• Sight distance considerations

• Horizontal alignment details

• Vertical alignment details

• Intersection elements

Under cross section elements, the considerations for the width of pavement, formation and

land, the surface characteristics and cross slope of pavement are included. The sight distance

visible clear ahead of the driver at horizontal and vertical curves and at intersections govern

the safe movements of vehicles.

The geometric design of highways depends on several design factors as:

• Design speed

• Topography or Terrain

• Traffic factors

• Design hourly volume and capacity

• Environmental and other factors



HIGHWAY CROSS SECTION ELEMENTS

PAVEMENT SURFACE CHARACTERISTICS

The pavement surface depends on pavement type. The important pavement surface

characteristics are:

• Friction

• Unevenness

• Light reflecting characteristics

• Drainage of surface water

CROSS SLOPE OR CAMBER

Cross slope or camber is the slope provided to the road surface in the transverse direction to

drain off the rainwater.

The values of camber recommended by IRC for different types of road surfaces are given in

the table below:

Sr.

No. Type of Road Surface

Range of camber in areas of

Heavy rain fall Low rain fall

1 Cement concrete and high type

bituminous surface 1 in 50 or 2.0 % 1 in 60 or 1.7 %

2 Thin bituminous surface 1 in 40 or 2.5 % 1 in 50 or 2.0 %

3 Water bound macadam and gravel

pavement 1 in 33 or 3.0 % 1 in 40 or 2.5 %

4 Earth road 1 in 25 or 4.0 % 1 in 33 or 3.0 %

The cross slope for shoulders should be 0.5 % steeper than the cross slope od adjoining

pavement, subject to a minimum of 3.0 % and a maximum value of 5.0 % for earth shoulders.

The cross slope suggested for the carriageway, paved shoulders and edge strips of

expressways with bituminous surface as well as cement concrete surface is 2.5 % in regions

with rainfall exceeding 1000 mm and 2.0 % in places with less than 1000 mm rainfall.

Camber are of three shapes:

• Parabolic Shape

• Straight line shape



• Combination of parabolic and straight-line shape

For providing parabolic camber on field general equation y = x2/a may be adopted, where a

= nW/2; n is the cross slope and W is width of the pavement.

Providing straight line camber is very simple and equation W/2n is adopted to determine the

height of the raised middle point (crown) of the pavement with respect to the edges.

QUESTION:

In a district where the rainfall is heavy, two types of road pavement are to be

constructed:

(a) Two lane State Highway with bituminous concrete surface

(b) Major District Road of WBM pavement, 3.8 m wide

What should be the height of the crown with respect to the edges in these two cases,

assuming straight line camber?

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………..……………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

…………………..…………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

……………………………………………………………………………..………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………..……………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



WIDTH OF PAVEMENT OR CARRIAGEWAY

The width of pavement or carriageway depends on (i) width of traffic lane and (ii) number

of lanes. The portion of carriageway width that is intended for one line of traffic movement

is called traffic lane.

The width of carriageway for various classes of roads standardized by the Indian Roads

Congress (IRC) are given in table below:

Class of Road Width of Carriageway, m

Single lane road 3.75

Two lanes, without raised kerbs 7.0

Two lanes, with raised kerbs 7.5

Intermediate carriageway 5.5

Multi-lane pavements 3.5 per lane

MEDIANS OR TRAFFIC SEPARATORS

In highways with divided carriageway, a median is provided between two sets of traffic

lanes intended to divide the traffic moving in opposite directions.

The function of the median is to avoid head-on-collision between vehicles moving in

opposite directions on adjacent lanes.

KERBS

Kerb indicates the boundary between the pavement and median or foot path or island or

shoulder. It is desirable to provide kerbs on urban roads.

Kerbs are divided into three types:

• Low Kerb or Mountable type kerb (100 mm above pavement)

• Semi-barrier type kerb (150 mm above pavement with a batter of 1:1 on the top 75

mm)

• Barrier type kerb (200 mm above pavement with a batter of 1 vertical to 0.25

horizontal)

ROAD MARGINS

The various elements included in road margins are shoulder, guard rail, foot path, driveway,

cycle track, parking lane, bus bay, lay-bye, frontage road and embankment slope.



WIDTH OF FORMATION OR ROADWAY

Width of formation or roadway is the sum of widths of pavement or carriageway including

separators, if any and the shoulders. It is the top width of the highway embankment or the

bottom width of highway cutting excluding the side drains.

Width of roadway for various classes of roads as per IRC is given in the table below:

Sr.

No.

Road

Classification

Roadway width, m

Plain & Rolling

Terrain

Mountainous &

Steep Terrain

1

National & State Highways

Single lane 12.0 6.25

Two lanes 12.0 8.80

2

Major District Roads

Single lanes 9.0 4.75

Two lanes 9.0 -

3

Other District Roads

Single lane 7.5 4.75

Two lanes 9.0 -

4 Village roads

Single lane 7.5 4.0

RIGHT OF WAY AND LAND WIDTH

Right of way is the area of land acquired for the road along its alignment. The width of

acquired land for right of way is known as land width.

Sr.

No.

Road

Classification

Plain & rolling Terrain Mountainous Terrain

Open Areas Built-up Areas Open

Areas

Built-up

Areas

Normal Range Normal Range Normal Normal

1 Expressways 90 - - - - -

2 National & State

Highways 45 30-60 30 30-60 24 20

3 Major District

Roads 25 25-30 20 15-25 18 15

4 Other District

Roads 15 15-25 15 15-20 15 12

5 Village Roads 12 12-18 10 10-15 9 9



Draw Cross section of VR or ODR in embankment in rural area

Draw Cross section of MDR in cutting in rural area

Draw cross section of NH or SH in rural area

Draw cross section of two-lane city road in built up area

Draw cross section of divided highway in urban area



SIGHT DISTANCE

Sight distance is the length of road visible ahead to the driver at any instance. Sight distance

available at any location of the carriageway is the actual distance a driver with his eye level

at a specified height above the pavement surface has visibility of any stationary or moving

object of specified height which is on the carriageway ahead. The sight distance between the

driver and the object is measured along the road surface.

STOPPING SIGHT DISTANCE

The minimum distance visible to a driver ahead or the sight distance available on a highway

at any spot should be of enough length to safely stop a vehicle travelling at design speed,

without collision with any other obstruction.

To determine stopping sight distance following parameters are required:

• Design Speed, V (m/s or km/Hr)

• Reaction time of driver, t seconds

• Gravitational acceleration, g

• Coefficient of longitudinal friction, f

• Gradient, n

If braking efficiency is given then it must be multiplied with coefficient of friction.

Stopping sight distance on a level road:

SSD (m) = lag distance + braking distance = vt + v2/2gf ………v is in m/s

SSD (m) = lag distance + braking distance = 0.278 Vt + V2/254f ………V is in km/Hr

Stopping sight distance at slopes:

+ve sign for ascending slope and -ve sign for descending slope

SSD (m) = lag distance + braking distance = vt + v2/2g (f ± 0.01n) ………v is in m/s

SSD (m) = lag distance + braking distance = 0.278 Vt + v2/254 (f ± 0.01n) ………V is in

km/Hr

Recommended coefficient of longitudinal friction for SSD

Speed,

kmph

20 to 30 40 50 60 65 80 100 &

above

f 0.40 0.38 0.37 0.36 0.36 0.35 0.35



QUESTION:

Calculate safe stopping sight distance on a level road stretch for design speed of 50

kmph for (a) two-way traffic on a two-lane road (b) two-way traffic on a single lane

road. Assume coefficient of friction as 0.37 and reaction time of driver as 2.5 seconds.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



QUESTION:

Calculate the minimum sight distance required to avoid a head on collision of two cars

approaching from the opposite directions at 90 and 60 kmph. Assume a reaction time

of 2.5 seconds, coefficient of friction 0.7 and a brake efficiency of 50 percent in both

cases.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



QUESTION:

Calculate the stopping sight distance on highway at a descending gradient of 2% for a

design speed of 80 kmph. Assume other data as per IRC recommendations.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



QUESTION:

The design speed of a road is 65 kmph, the coefficient of friction is 0.36 and reaction

time of driver is 2.5 seconds. Calculate the values of (a) Head light sight distance and

(b) Intermediate sight distance required for the road.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



OVERTAKING SIGHT DISTANCE

The minimum distance open to the vision of the driver of a vehicle intending to overtake

slow vehicle ahead with safety against the traffic of opposite direction is known as the

minimum overtaking sight distance (OSD) or the safe passing sight distance available.

OSD in metres is the summation of the following three distances:

1) d1 = vbt = 2vb

2) d2 = vbT + 2S

• S = 0.7 vb + 6

• T = √4𝑆

𝑎

3) d3 = vT

Where vb = speed of overtaken vehicle in m/s

t = reaction time of driver, 2 seconds

T = overtaking time in seconds

S = minimum spacing between vehicles in m

a = acceleration in kmph/sec

v = speed of overtaking vehicle in m/s

OSD = d1 + d2 + d3 = vbt + vbT + 2S + vT……….. where v and vb are in m/s

OSD = d1 + d2 + d3 = 0.28Vbt + 0.28VbT + 2S + 0.28VT… where V and Vb are in km/h

In case of one-way traffic on road, OSD = d1 + d2

In case of two-way traffic on road, OSD = d1 + d2 + d3

Minimum length of overtaking zone in metres = 3 (OSD)

Desirable length of overtaking zone in metres = 5 (OSD)

In case the speed of overtaking vehicles is not given, the same may be assumed as 4.5 m/s

or 16 kmph less than the design speed of the highway.



Maximum overtaking acceleration at different speeds is given in table below:

Speed Maximum overtaking

acceleration

V,

kmph

V,

m/sec A, kmph/sec a, m/sec2

25 6.93 5.00 1.41

30 8.34 4.80 1.30

40 11.10 4.45 1.24

50 13.86 4.00 1.11

65 18.00 3.28 0.92

80 22.20 2.56 0.72

100 27.80 1.92 0.53

QUESTION:

The speeds of overtaking and overtaken vehicles are 70 and 40 kmph, respectively on

a two-way traffic road. The average acceleration during overtaking may be assumed

as 0.99 m/sec2.

(a) Calculate safe overtaking sight distance

(b) What is the minimum and desirable length of overtaking zone?

(c) Draw a neat sketch of the overtaking zone and show the positions of the

signposts.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



QUESTION:

Calculate the safe overtaking sight distance for a design speed of 96 kmph. Assume

all other data suitably.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



DESIGN OF HORIZONTAL ALIGNMENT

Various design elements to be considered in the horizontal alignment are design speed,

radius of circular curve, type and length of transition curves, super elevation, widening of

pavement on curves and required set back distance for fulfilling sight distance requirements.

The design speed is the main factor governing geometric design elements. The design speed

of road depends upon (i) class of the road and (ii) terrain.

The terrains are classified as below:

Terrain

classification

Cross slope of the country

(%)

Plain 0 – 10

Rolling 10 – 25

Mountainous 25 – 60

Steep Greater than 60

The ruling and minimum design speed values standardized by the IRC for different classes

of roads on different terrains in rural (non-urban) areas are given in below table:

Road Classification

Design speed in kmph for various terrains

Plain Rolling Mountainous Steep

Ruling Min. Ruling Min. Ruling Min. Ruling Min.

Expressways 120 100 100 80 80 60 80 60

National & State

Highways 100 80 80 65 50 40 40 30

Major District

Roads 80 65 65 50 40 30 30 20

Other District Roads 65 50 50 40 30 25 25 20

Village Roads 50 40 40 35 25 20 25 20

The recommended design speeds for different classes of urban roads are:

Arterial Roads: 80 kmph

Sub-Arterial Roads: 60 kmph

Collector Streets: 50 kmph

Local Streets: 30 kmph



SUPER ELEVATION

In order to counteract the effect of centrifugal force and to reduce the tendency of the vehicle

to overturn or skid, the outer edge of the pavement is raised with respect to the inner edge,

thus providing a transverse slope throughout the length of the horizontal curve. This

transverse inclination to the pavement surface is known as super elevation or cant or

banking.

The rate of super elevation is expressed as the ratio of the height of the outer edge with

respect to the horizontal width.

The general equation for design of superelevation is given by

e + f = v2/gR

where e = rate of superelevation

f = design value of lateral friction coefficient = 0.15

v = speed of the vehicle in m/sec

R = radius of the horizontal curve in m

g = gravitational acceleration in m/sec2

If the speed of the vehicle represented as V kmph then the equation is written as

e + f = V2/127R

where e = rate of superelevation

f = design value of lateral friction coefficient = 0.15

V = speed of the vehicle in kmph

R = radius of the horizontal curve in m

g = gravitational acceleration in m/sec2

The maximum value of super elevation is limited to 7 % or 0.07 however on hill roads up

to 10 % or 0.1 has been recommended by IRC and the maximum value of lateral friction

coefficient, f taken for design of highways is 0.15

In some cases, it may not be possible to provide superelevation and so friction counteracts

the centrifugal force fully. And so, the allowable speed of vehicle negotiating a turn should

be restricted.

V = (127fR)1/2



STEPS FOR DESIGN OF SUPERELEVATION

• The superelevation is calculated for 75 % of design speed neglecting the friction

o e = (0.75𝑣)2

𝑔𝑅 or e =

(0.75𝑉)2

127𝑅

o i.e, e = 𝑉2

225𝑅

• If the calculated value of ‘e’ is less than 7% or 0.07 the value so obtained is provided.

If the value of ‘e’ as per above equation exceeds 0.7 then provide the maximum

superelevation equal to 0.07 and proceed with further steps.

• Check the coefficient of friction developed for the maximum value of e = 0.07 at the

full value of design speed, v m/sec or V kmph

o e = 𝑣2

𝑔𝑅 − 0.07 or e =

𝑉2

127𝑅− 0.07

o If the value of ‘f’ thus calculated is less than 0.15, the superelevation of 0.07

is safe for the design speed and this is accepted as the design superelevation.

o If not, either the radius of the horizontal curve has to be increased or the

speed has to be restricted to the safe value which will be less than the design

speed.

• The allowable speed or restricted speed (va m/sec or Va kmph) at the curve is

calculated by considering the design coefficient of lateral friction and the maximum

superelevation, i.e.,

o e +f = 0.07 + 0.15 = 0.22 = va2/gR = Va

2/127R

o va = (2.156R)1/2 m/sec or Va = (27.94R)1/2

• If the allowable as calculated above is higher than the design speed, then the design

speed is adequate and provide superelevation of ‘e’ equal to 0.07. if the allowable

speed is less than the design speed, the speed is limited to the allowable speed Va

kmph calculated above.



QUESTION:

The radius of a horizontal circular curve is 100 m. The design speed is 50 kmph and

the design coefficient of lateral friction is 0.15.

(a) calculate the superelevation required if full lateral friction is assumed to develop.

(b) calculate the coefficient of friction needed if no superelevation is provided.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

QUESTION:

A two-lane road with design speed 80 kmph has horizontal curve of radius 480 m.

Design the rate of superelevation for mixed traffic. By how much should the outer

edges of the pavement be raised with respect to the inner edge, if the width of the

pavement at the horizontal curve is 7.5 m.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

QUESTION:

Design the rate of superelevation for a horizontal highway curve of radius 500 m and

speed 100 kmph.

SOLUTION:

……………………………………………………………………………………………….

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

QUESTION:

The design speed of a highway is 80 kmph. There is a horizontal curve of radius 200 m

on a certain locality. Safe limit of transverse coefficient of friction is 0.15.

(a) Calculate the superelevation required to maintain this speed.

(b) If the maximum superelevation of 0.07 is not be exceeded, calculate the maximum

allowable speed on this horizontal curve as it is not possible to increase the radius.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

QUESTION:

A major district road with thin bituminous pavement surface in low rainfall area has

horizontal curve of radius 1400 m. If the design speed is 65 kmph, what should be the

superelevation? Discuss your answer.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

RADIUS OF HORIZONTAL CURVE

Horizontal curves of highways are generally designed for the specified ruling design speed

of the highway. However, if this is not possible due to site restrictions, the horizontal curves

may be designed considering the specified minimum design speed of the highway.

If the design speed is decided for a highway, then the minimum radius to be adopted can be

found from the above relationship. Thus the ruling minimum radius of the curve, Rruling for

ruling design speed v m/sec or V kmph is given by:

RRuling = v2 / (e + f) g or RRuling = V2 / 127 (e + f)

If the minimum design speed is V’ kmph, the absolute minimum radius of horizontal curve

Rmin is given by:

Rmin = V’2 / 127 (e + f)

QUESTION:

Calculate the values of ruling minimum radius and absolute minimum radius of

horizontal curve of a National Highway in plain terrain. Assume ruling design speed

and minimum design speed values as 100 and 80 kmph respectively.

SOLUTION:

………………………………………………………………………………………………

…………………………………………………………………………….…………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

WIDENING OF PAVEMENT ON HORIZONTAL CURVES

On horizontal curves, especially when they are not of very large radii, it is a common

practice to widen the pavement slightly more than the normal width.

The required extra widening of the pavement at the horizontal curves, We depends on (i)

the length of wheel base ‘l’ of the vehicle (ii) radius of the curve negotiated, R (iii) the

psychological factor which is a function of the speed of the vehicle and the radius of the

curve.

The extra widening of pavement on horizontal curves is divided into two parts (i)

Mechanical widening and (ii) Psychological widening

Mechanical Widening, Wm = nl2/2R

Where, n = number of traffic lanes

l = length of wheelbase of longest vehicle which may normally be taken as

6.0 m for commercial vehicles

R = Radius of horizontal curve

Psychological Widening, Psy = V / 9.5 (R)1/2

Where, V = Design speed in kmph

Extra Widening, We = Mechanical Widening, Wm + Psychological Widening, Psy

= nl2 / 2R + V / 9.5 (R)1/2



QUESTION:

Calculate the extra widening required for a pavement of width 7.0 m on a horizontal

curve of radius 200 m if the longest wheelbase of vehicle expected on the road is 6.5

m. Design speed is 65 kmph.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

……...………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

QUESTION:

Find the total width of a pavement on a horizontal curve for a new national highway

to be aligned along a rolling terrain with a ruling minimum radius. Assume necessary

data.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

……...………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

HORIZONTAL TRANSITION CURVE

A horizontal transition curve has a radius which decreases from infinity at the tangent point

to a designed radius of the circular curve. When a transition curve is introduced between a

straight and circular curve, the radius of transition curve decreases and becomes minimum

at the beginning of the circular curve. The rate of change of radius of the transition curve

will depend on the shape of the curve adopted and the equation of the curve.

Types of transition curves commonly adopted in horizontal alignment of highways are: (i)

Spiral (ii) Lemniscate (iii) Cubic parabola. IRC recommends the use of spiral as transition

curve.

The length of transition curve is designed to fulfill three conditions, viz: (i) rate of change

of centrifugal acceleration to be developed gradually (ii) rate of introduction of the designed

superelevation to be at a reasonable rate (iii) minimum length by IRC empirical formula.

Length of Transition Curve (Ls) According to Rate of change of centrifugal

acceleration

C m/sec3 = v3 / Ls R

Thus Ls = v3/CR…… v is in m/sec

C = 80 / (75 + V), the value must be in between 0.5 and 0.8

Ls = 0.0215 V3 / CR…….. V is in kmph

Length of Transition Curve (Ls) According to Rate of introduction of super elevation

Ls = EN / 2 = eN (W + We) / 2 ……………. Pavement is rotated about center line

Where N = 1 in 150 desirable

= 1 in 100 in built up areas

= 1 in 60 on hill roads

W = width of pavement

We = extra widening of pavement on curves

Ls = EN = eN (W + We) ……………. Pavement is rotated about inner edge

Length of Transition Curve (Ls) According to Empirical Formula as per IRC

Ls = 2.7 V2 / R ……… For Plain and Rolling Terrain



Ls = V2 / R ……… For Mountainous and Steep Terrain

Adopt the highest value of Ls as the design length of transition curve.

Setting Out Transition Curve

The shift S of the transition curve is given by, S = Ls2 / 24R

QUESTION:

Calculate (a) the length of transition curve and (b) shift of the transition curve using

the following data:

Design Speed = 65 kmph

Radius of circular curve = 220 m

Pavement width including extra widening = 7.5 m

Allowable rate of introduction of superelevation = 1 in 150

Assume pavement is rotated about the center line

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



QUESTION:

A national highway passing through rolling terrain in heavy rainfall area has a

horizontal curve of radius 500 m. Design the length of transition curve assuming

suitable data.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



SETBACK DISTANCE ON HORIZONTAL CURVES

In the design of horizontal alignment, the sight distance along the inner side of the

horizontal curves should be considered. Where the sight distance is limited due to the

presence of obstructions to vision like buildings, cut slopes or tree on the inner side of the

curves, either the obstruction should be removed, or the alignment should be changed in

order to provide adequate sight distance.

The set back distance or clearance required from the center line of a horizontal curve to an

obstruction on the inner side of the curve to provide adequate sight distance depends on:

o Required sight distance, S

o Radius of horizontal curve, R

o Length of the curve Lc, which may be greater or lesser than S

Setback distance (m) when Lc > S

In case of single lane road

m = R – R cos 𝛼

2

𝛼

2 =

180 𝑆

2 𝜋 𝑅 𝑑𝑒𝑔𝑟𝑒𝑒𝑠

In case of multi lane road

m' = R – (R – d) cos 𝛼′

2

𝛼′

2 =

180 𝑆

2 𝜋 (𝑅−𝑑) 𝑑𝑒𝑔𝑟𝑒𝑒𝑠

Where, d = distance between the center line of the road and the center line of the inside

lane on metres

Setback distance (m) when Lc < S

In case of single lane road

m = R – R cos 𝛼

2 +

(S − Lc)

2sin

𝛼

2

𝛼

2 =

180 𝐿𝑐

2 𝜋 𝑅 𝑑𝑒𝑔𝑟𝑒𝑒𝑠

In case of multi lane road

m' = R – (R – d) cos 𝛼′

2 +

(S − Lc)

2sin

𝛼′

2



𝛼′

2 =

180 𝐿𝑐

2 𝜋 (𝑅−𝑑) 𝑑𝑒𝑔𝑟𝑒𝑒𝑠

Where, d = distance between the center line of the road and the center line of the inside

lane on metres

QUESTION:

A two-lane highway has a horizontal curve of radius 250 m and the total pavement

width is 7.6 m at the curve. A minimum sight distance of 240 m is to be provided at

this curve. Assuming the length of the curve to be greater than the sight distance,

determine the setback distance up to which all obstructions should be removed.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



QUESTION:

A two-lane highway has a horizontal curve of radius 200 m and the total length of the

curve is 240 m. The distance between the center line of the highway and the center of

inner lane is 1.95 m at the curve. If the desired sight distance is 340 m, determine the

set-back distance required.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



QUESTION:

While aligning a highway in a built-up area, it was necessary to provide a horizontal

circular curve of radius 325 m. the design speed is 65 kmph, length of wheel base of

largest truck is 6.0 m and width of pavement is 10.5 m. Design (i) Superelevation (ii)

Extra widening of pavement (iii) Length of transition curve.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



QUESTION:

A state highway passing through a rolling terrain has a horizontal curve of radius

equal to the ruling minimum radius.

(i) Design all the geometric features of this horizontal curve, assuming suitable data

(ii) Determine setback distance considering ISD. Assume Lc > Sight Distance.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



DESIGN OF VERTICAL ALIGNMENT

The natural ground or the topography may be level at some places but may have slopes of

varying magnitudes at other locations. While aligning a highway it is the common practice

to follow the general topography or profile of th eland, keeping in view to minimize deep

cuttings and very high embankments.

The vertical alignment is the elevation or profile of the center line of the road. The vertical

alignment consists of grades and vertical curves. The vertical alignment of a highway

influences: (i) vehicle speed (ii) acceleration and deceleration (iii) stopping distance (iv)

sight distance (v) comfort while travelling at high speeds and (vi) vehicle operation cost.

Gradients are classified into (i) Ruling gradient (ii) Limiting Gradient (iii) Exceptional

Gradient (vi) Minimum gradient

GRADE COMPENSATION

When there is a horizontal curve in addition to the gradient, there will be increased

resistance to traction due to both horizontal curve and gradient; in other words, the total

resistance will be (grade resistance + curve resistance). In such cases the gradient should

be decreased to compensate for the loss of tractive effort due to curve. This reduction in

gradient at the curve is called grade compensation.

Grade Compensation, % = (30 + R) / R

The maximum value of grade compensation is limited to 75 / R, where R is the radius of

the circular curve.

According to IRC the grade compensation is not necessary for gradient flatter than 4% and

thus when applying grade compensation correction, the gradients need not be eased beyond

4%. The compensated gradient is = ruling gradient – grade compensation

QUESTION:

While aligning a hill road with a ruling gradient of 6 %, a horizontal curve of radius

60 m is encountered. Find the grade compensation and the compensated gradient at

the curve.

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



VERTICAL CURVES

Dur to changes in grade in the vertical alignment of highway, it is necessary to introduce

vertical curve at the intersections of different grade to smoothen out the vertical profile and

thus ease off the changes in gradients for the fast-moving vehicles.

The vertical curves used in highway may be classified into two categories:

(a) Summit curves or crest curves with convexity upwards

(b) Valley curves or sag curves with concavity upwards

SUMMIT CURVES

The design of summit curves is governed only by considerations of sight distance and thus

transition curves are not necessary.

Length of Summit Curve for SSD

Two cases are to be considered in deciding the length of summit curve:

o When the length of curve is greater than sight distance (L > SSD)

L =NS2

[√2H+√2h]2 =

NS2

4.4

Where, L = length of summit curve, m

S = Stopping sight distance, m

N = deviation angle

H = height of eye level of driver above road surface, m = 1.2 m

h = height of subject above the pavement surface, m = 0.15 m

o When the length of curve is less than sight distance (L < SSD)

L = 2s −[√2H+√2h]

2

N = 2S -

4.4

𝑁



Length of Summit Curve for OSD or ISD

Two cases are to be considered in deciding the length of summit curve:

o When the length of curve is greater than sight distance (L > OSD or ISD)

L = NS2

8𝐻 =

NS2

9.6

Where, L = length of summit curve, m

S = Stopping sight distance, m

N = deviation angle

H = height of eye level of driver above road surface, m = 1.2 m

h = height of subject above the pavement surface, m = 0.15 m

o When the length of curve is less than sight distance (L < OSD or ISD)

L =2S - 8𝐻

𝑁 = 2S -

9.6

𝑁

VALLEY CURVES

The valley curves are designed as transition curves to fulfill the two criteria (i) the allowable

rate of change of centrifugal acceleration and (ii) the required head light sight distance for

night driving. The higher of the two values is adopted.

Length of Valley Curve for comfort condition

L = 2LS = 2 [Nv3

C]

12⁄

Where L = Total length of valley curve

N = deviation angle

V = design speed in m/s

C = allowable rate of change of centrifugal acceleration which may be taken as 0.6

m/sec3



Length of Valley Curve for head light sight distance

Two cases are to be considered in deciding the length of valley curve:

o When the length of curve is greater than sight distance (L > SSD)

L =NS2

[1.5 + 0.035 S]

o When the length of curve is less than sight distance (L < SSD)

L = 2S − (1.5 + 0.035S

N)

QUESTION:

A vertical summit curve is formed at the intersection of two gradients, +3.0 % and -

5.0 %. Design the length of summit curve to provide a stopping sight distance for a

design speed of 80 kmph. Assume other data.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

QUESTION:

An ascending gradient of 1 in 100 meets a descending gradient of 1 in 120. A summit

curve is to be designed for a speed of 80 kmph so as to have an overtaking sight

distance of 470 m

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

QUESTION:

A vertical summit curve is to be designed when two grades, +1 / 50 and – 1 / 180 meet

on a highway. The stopping sight distance and overtaking sight distance required are

180 and 640 m respectively. But due to site conditions the length of vertical curve has

to be restricted to a maximum value of 500 m if possible. Calculate the length of

summit curve needed to fulfill the requirements of (a) Stopping sight distance (b)

Overtaking sight distance or at least intermediate sight distance and discuss the

results.

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



QUESTION:

A valley curve is formed by a descending grade of 1 in 25 meeting an ascending grade

of 1 in 30. Design the length of valley curve to fulfill both comfort condition and head

light sight distance requirements for a design speed of 80 kmph. Assume allowable

rate of change of centrifugal acceleration C = 0.6 m/sec3

SOLUTION:

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………

………………………………………………………………………………………………



OTHER QUESTIONS:

UNIT-1

QUESTION: What are the significant recommendations of Jayakar Committee

Report?

QUESTION: Explain briefly modified classification of road system in India as per

third twenty-year road development plan.



Question: The following data were collected for planning the road development of a

backward district:

(1) Total area = 12000 sq.km.

(2) Agricultural area = 5000 sq.km.

(3) Existing rail length = 150 km

(4) Existing surface road = 350km

(5) Existing Un-surfaced road = 450km

(6) Town-Population data:

Calculate:

(a) Total & Additional length of surface road

(b) Total & Additional length of Un-surfaced road

Population >5000 2001-5000 1001-2000 501-1000 <500

Towns 15 60 200 300 500



QUESTION: Define highway alignment. Discuss briefly the basic requirements of an

ideal road alignment.



UNIT - 2

QUESTION: Explain PIEV theory and draw neat sketch showing PIEV concept.



UNIT - 4

QUESTION: Explain briefly factors considered for the design of flexible pavements?

QUESTION: Explain briefly factors considered for the design of rigid pavements?



QUESTION: What is the difference between flexible and rigid pavements? Discuss

about pavement components with sketch.



QUESTION: Write down the construction procedure for water bound macadam.



QUESTION: Write down the construction procedure for bituminous road.



QUESTION: Write down the construction procedure for cement concrete road. Also

give details about joints in cement concrete road by drawing neat sketch.



UNIT - 5

QUESTION: Write short note on (a) Street lighting (b) Road arboriculture



QUESTION: Discuss about failures in flexible and rigid pavements.



QUESTION: Write a short note on prevention of land slides

QUESTION: Write significance of highway drainage



QUESTION: Explain surface drainage and subsurface drainage by drawing neat

sketch.



UNIT - 6

QUESTION: Explain relationship between traffic flow parameters by drawing neat

sketch.



QUESTION: What are the preventive measures of accident?



QUESTION: Discuss about road user characteristics.



QUESTION: Define traffic volume, traffic density, PCU, spot speed, running speed,

journey speed, time mean speed, space mean speed.

QUESTION: Draw STOP and GIVE WAY signs.



QUESTION: Draw rotary intersection, full clover leaf, partial clover leaf and

diamond interchanges.



SECTION-H

FIELD TESTS ON PAVEMENT LAYERS


26 Determination of Field Density of Pavement Layer IS: 2720 Part 28 & 29-1975

27 Introduction of Plate Bearing Test IS: 9214-1979

28 Introduction of Benkelman Beam Deflection IRC: 81-1997

29 Introduction Unevenness Measurement by Bump

Integrator and MERLIN

IRC: SP: 16 – 2004 & IRC:

82-2015



EXPERIMENT NO: 26 Date:___/___/_____

DETERMINATION OF FIELD DENSITY OF PAVEMENT LAYER

(IS:2720 PART 28 – 1975 & IS: 2720 PART 29 – 1975)

Determination of field density by sand replacement method:

A simple and most common method of determination of in-place field density of soil and

other compacted pavement layer is the ‘sand replacement method’. The basic principal of

sand replacement method is to measure the in-place volume of a hole from which the

material was excavated, by filling-in the hole with dry sand of known density. The sand

poring cylinder apparatus is used for this purpose. The in-place density of material is given

by the weight of the excavated material collected from the hole, divided by the in-place

volume of the hole. In-place dry density is determined by finding the moisture content in

the soil collected from the field.

OBJECTIVE:

• To determine in-place dry density of natural or compacted material.

APPARATUS:

• Small sand poring cylinder for fine and medium grained soils; large sand pouring

cylinder for coarse grained soils (can also be used for fine and medium grained

soils)

• Tools for excavating holes

• Cylindrical calibrating container

o 100 mm internal diameter & 150 mm depth (for small pouring cylinder)

o 200 mm internal diameter & 250 mm depth (for large pouring cylinder)

• Balance

• Sand passing 1.00 mm sieve and retain on 600 micron sieve.

• Plane surface

• Metal containers

• Metal tray with central hole

o 300 mm square, 40 mm deep, 100 mm hole in centre (for small pouring

cylinder)

o 450 mm square, 50 mm deep, 200 mm hole in centre (for small pouring

cylinder)



TEST PROCEDURE:

For Calibration

• The pouring cylinder shall be filled with a given initial weight of sand W1. This weight

shall be maintained constant through out the tests for which the calibration is used.

• The shutter on the pouring cylinder shall be opened and sand allowed to run out. When

non further movement of sand takes place in the cylinder the shutter shall be closed, and

the cylinder removed carefully.

• The sand that has filled the cone of the pouring cylinder shall be collected and weighed

W2.

• These measurements shall be repeated at least three times and mean weight W2 of cone

is taken.

• The internal volume V in ml of the calibrating container shall be determined by the

weight of water contained in the container when filled to the brim.

• The pouring cylinder shall be placed concentrically on the top of the calibrating

container and filled with constant weight of sand W1.

• The shutter on the pouring cylinder shall be closed during this operation.

• The shutter shall be opened, and the sand allowed to run out.

• When non further movement of sand takes place in the cylinder the shutter shall be

closed, and the cylinder removed carefully and the remaining sand in it is weighed.

• These measurements shall be repeated at least three times and mean weight W3.

For Soil Density

• A flat area, at the place at which the soil is to be tested shall be exposed and trimmed

down to a level surface.

• The metal tray with a central hole shall be laid o the prepared surface of the soil with the

hole over the potion of the soil to be tested.

• The hole in the soil shall then be excavated using the hole in the tray as a pattern, to a

depth of the layer to be tested.

• Th excavated soil shall be carefully collected leaving no loose material in the hole and

weighed to the nearest gram WW.

• The metal tray shall be removed before the pouring cylinder is placed in position over

the excavated hole.

Metal tray with hole

Sand pouring cylinder

Cylindrical calibrating container



• A representative sample of the excavated soil shall be placed in an air-tight container

and its water content w is determined.

• The pouring cylinder filled with constant weight of sand W1, shall be placed so that the

base of the cylinder covers the hole concentrically.

• The shutter on the pouring cylinder shall be closed during this operation. The shutter

shall then be opened, and sand allowed to run out.

• When no further movement of the sand takes place, the shutter shall be closed.

• The cylinder shall be removed and the sand remaining in it weighed W4.

OBSERVATION:

For Calibration

Mean weight of sand in cone of pouring cylinder, W2 g

Volume of calibrating cylinder, V ml

Weight of sand (+ cylinder) before pouring, W1 g

Weight of sand (+ cylinder) after pouring, W3 g

Weight of sand to fill calibrating container, Wa g = W1 – W3 – W2

Bulk density of sand, γs = (Wa / V) x 1000 kg/m3

For Soil Density

Weight of wet soil from hole, Ww g

Weight of sand (+ cylinder) after pouring, W4 g

Weight of sand to in hole, Wa g = W1 – W4 – W2

Volume of Hole, Vh = (Wa / γs) x 1000 kg/m3

Bulk density of soil, γb = Ww / Vh

Weight of soil for water content determination in g

Weight of oven dry oil in g

Water content, w %

Dry Density = (γb / 1 + w)



Determination of field density by core cutter method:

APPARATUS:

• Cylindrical core cutter of seamless steel tube, 130 mm long and 10 cm internal

diameter, with a wall thickness of 3mm, beveled at one end.

• Steel Dolly 2.5 cm high and 10 cm internal diameter with a wall thickness of 7.5 mm.

• Steel Rammer with solid mild steel foot 140 mm diameter and 75 mm height and

weight 9 kg.

• Balance

• Palette knife

• Steel rule

• Grafting tool or Spade or Pickaxe

• Straight edge

• Apparatus for extracting sample from the cutter

• Apparatus for determination of water content.



TEST PROCEDURE:

• The internal volume, VC of the core-cutter in cubic centimetres shall be calculated

from its dimensions which shall be measured to the nearest 0.25 mm.

• The cutter shall be weighed to the nearest gram, WC.

• A small area, approximately 30 cm square of the soil layer to be tested shall be

exposed and levelled. The steel dolly shall be placed on top of the cutter and the

latter shall be rammed down vertically into the soil layer until only about 15 mm of

the dolly protrudes above the surface, care being taken not to rock the cutter.

• The cutter shall then be dug out of the surrounding soil, care being taken to allow

some soil to project from the lower end of the cutter. The ends of the soil core shall

then be trimmed flat to the ends of the cutter by means of the straight edge.

• The cutter containing the soil core shall be weighed to the nearest gram Ws g

• The soil core shall be removed from the cutter and a representative sample shall be

placed in an air-tight container and its water content

CALCULATIONS:

Bulk Density, γb = (Ws – Wc) / Vc =

Where Ws = weight of soil and core-cutter in g,

Wc = weight of core-cutter in g.

Vc = volume of core-cutter in cm3

Dry Density, γd = (100 x γb) / (100 + w) =

Where γb = bulk density

W = water content of soil




INTRODUCTION OF PLATE BEARING TEST (IS: 9214-1979)

The Plate Bearing Test is used to evaluate the support capability of sub-grades, bases and

in some cases, complete pavement. Data from the tests are applicable for the design of both

flexible and rigid pavements. In plate bearing test, a compressive stress is applied to the

soil or pavement layer through rigid plates relatively large size and the deflections are

measured for various stress values. The deflection level is generally limited to a low value,

in the order of 1.25 to 5 mm and so the deformation caused may be partly elastic and partly

plastic due to compaction of the stressed mass with negligible plastic deformation. The

plate-bearing test has been devised to evaluate the supporting power of sub grades or any

other pavement layer by using plates of larger diameter. The plate-bearing test was

originally meant to find the modulus of sub grade reaction in the Westergaard's analysis for

wheel load stresses in cement concrete pavements.

APPARATUS:

• Bearing Plates - Circular bearing plates of mild steel, 75 cm diameter and 25 mm

thickness. Smaller bearing plates of 45, 40 or 30 cm may also be used.

• Loading Attachment – Loads are applied by means of a hydraulic jack or screw

jack working against a reaction frame through bearing plates. The loading

attachment should have a capacity of at least 150 kN.

• Jacks – Hydraulic or screw jack of 150 kN capacity

• Proving Ring – Calibrated proving ring of capacity 150 kN.

• Loading Reaction – The reaction for jacking can be provided by a truck, trailer or

anchor frame such that its reaction shall be at least 2.5 m away from the centre of

the bearing plates.

• Dial Gauges – Three numbers of dial gauges with an accuracy of 0.002 mm are

desirable.

• Jack Pads – Due to variation in the depth of test points some distance pieces, for

example, spacers will be required between jack and proving ring. The exact

requirement of these jack pads will vary from one test point to another according to

depth of test points below ground surface.

• Stiffening Plates – These are mild steel plates of 60, 45 and 30 cm diameter and 25

mm thickness.

• Miscellaneous Apparatus – Datum bar of 5 m length with suitable dial gauge

attachment, pickaxes, showel, trowel, spatula, spirit level and plumb bob.



TEST PROCEDURE:

• The test site is prepared, and loose material is removed so that the 75 cm diameter

late rests horizontally in full contact with the soil sub-grade. The plate is seated

accurately and then a seating load equivalent to a pressure of 0.07 kg/cm2 (320 kg

for 75 cm diameter plate) is applied and released after a few seconds. The settlement

dial gauge is now set corresponding to zero load.

• A load is applied by means of jack, enough to cause an average settlement of about

0.25 cm. When there is no perceptible increase in settlement or when the rate of

settlement is less than 0.025 mm per minute (in the case of soils with high moisture

content or in clayey soils) the load dial reading, and the settlement dial readings are

noted.

• Deflection of the plate is measured by means of deflection dials; placed usually at

one-third points of the plate near its outer edge.

• To minimize bending, a series of stacked plates should be used.

• Average of three or four settlement dial readings is taken as the settlement of the

plate corresponding to the applied load. Load is then increased till the average

settlement increase to a further amount of about 0.25 mm, and the load and average



settlement readings are noted as before. The procedure is repeated till the settlement

is about 1.75 mm or more.

• Allowance for worst subgrade moisture and correction for small plate size should

be dealt properly.

CALCULATION:

• A graph is plotted with the mean settlement versus bearing pressure (load per unit

area). The pressure corresponding to a settlement is obtained from this graph. The

modulus of subgrade reaction is calculated from the relation.

𝐾 = 𝑃

0.125 kg/cm2/cm

MODULUS OF SUBGRADE REACTION:

• In case of homogeneous foundation, k-value obtained with 30cm diameter plate

can be converted to get k-value for 75 cm plate using following equation:

K75 = 0.5 x K30

• The ideal period for testing is during or soon after the monsoon (weakest condition)

• To adjust the K-vale obtained at any time to correspond to worst condition, CBR

tests on sub-grade soil samples compacted at field density and field moisture

content must be done before and after saturation.



• K-Value can be estimated from CBR value for homogeneous soil subgrade. IRC:

58 – 2015 recommends the following values.

Soaked

CBR value

(%)

2 3 4 5 7 10 15 20 50 100

K-Value

(kg/cm2/cm) 2.1 2.8 3.5 4.2 4.8 5.5 6.2 6.9 14.0 22.2




INTRODUCTION OF BENKELMAN BEAM DEFLECTION (BBD)

TECHNIQUE (IRC: 81 - 1987)

Benkelman Beam Deflection technique is widely used for evaluation of the requirements

of strengthening of flexible pavements.

Performance of flexible pavements is closely related to the elastic deflection of pavement

under the wheel loads. Pavement deflection is measured by the Benkelman Beam.

OBJECTIVE:

• To determine the rebound deflection of pavement under static load of the rear axle

of a standard truck.

EQUIPMENTS:

• Benkelman Beam

o Length of probe arm from pivot to probe point: 244 cm

o Length of measurement arm from pivot to dial: 122 cm

o Distance from pivot to front legs: 25 cm

o Distance from pivot to rear legs: 166 cm

o Lateral spacing of front support legs: 33 cm

• A 5 tonne truck is recommended as the reaction. The vehicle shall have 8170 kg

rear axle load equally distributed over the two wheels, equipped with dual tyres.

The tyres shall be inflated to pressure of 5.6 kg/cm2.

• Tyre pressure measuring gauge

• Thermometer (0-100oC) with 1o division

• A mandral for making 4.5 cm deep hole in the pavement for temperature

measurement. The diameter of the hole at the surface shall be 1.25 cm and at the

bottom 1 cm.



TEST PROCEDURE:

• The point on the pavement to be tested is selected. For highways the point should

be located 60 cm from the pavement edge if the lane width is less than 3.5 m and

90 cm from the pavement edge for wider lanes. For divided four lane highway, the

measurement points should 1.5 m from the pavement edge.

• The dual wheels of the truck are centered above selected point.

• The probe of the Benkelman beam is inserted between the duals and placed on the

selected point.

• The locking pin is removed from the beam and the legs are adjusted so that the

plunger of the beam is in contact with the stem of the dial gauge. The beam pivot

arms are checked for free movement.

• The dial gauge is set at approximately 1 cm. the initial reading is recorded when the

rate of deformation of the pavement is equal or less than 0.025 mm per minute.

• The truck is slowly driven at 2.7 m and stopped.

• An intermediate reading is recorded when the rate of recovery of the pavement is

equal to or less than 0.025 mm per minute.

• The truck is driven forward a further 9 m.

• The final reading is recorded when the rate of recovery of pavement is equal to or

less than 0.025 mm per minute.

• Pavement temperature is recorded at least once every hour inserting thermometer

in the standard hole and filling up the hole with glycerol.

• The tyre pressure is checked at two- or three-hour intervals during the day and

adjusted to the standard, if necessary.



CALCULATIONS:

• Subtract the final dial reading from the initial dial reading. Also subtract the

intermediate reading from the initial reading.

• If the differential readings obtained compare within 0.025 mm the actual pavement

deflection is twice the final differential reading.

• If the differential readings don not compare to 0.025 mm, twice the final differential

dial reading represents apparent pavement deflection.

• Apparent pavement deflection are corrected by means of the following formula:

o XT = XA + 2.91 y

Where XT = True pavement deflection

XA = Apparent pavement deflection

Y = Vertical movement of the front legs i.e., twice the difference

between the final and intermediate dial readings.

• The rebound deflection (%) shall be the twice of the XT value




INTRODUCTION OF SURFACE UNEVENNESS OF HIGHWAY

PAVEMENTS (IRC: SP: 16 – 2004 & IRC: 82 - 2015)

Surface unevenness affects vehicle speed, comfort, vehicle operating cost and safety and

hence needs to be given careful consideration during initial construction and subsequent

maintenance.

The roughness of pavement surface is commonly designated as Unevenness Index Value

and is expressed in surface roughness is measured by a bump integrator.

BUMP INTEGRATOR:

Either towed fifth wheel bump integrator or car mounted bump integrator can be used for

measuring the road roughness. These are response type road roughness measuring systems

and are extensively used in the country for measurement of roughness.

Towed Fifth Wheel Bump Integrator

• The indigenous version of this device is the Automatic Road Unevenness Research

(ARUR).

• The equipment consists of a trailer towed by a vehicle. A standard pneumatic tyre wheel

inflated to a pressure of 2.1 km/cm2 is mounted within the trailer chassis, with a single

leaf spring on either side of the wheel supporting the chassis.

• Two dashpots provide viscous damping between chases and axle.

• The frame is provided with a counterweight at the front to make the device practically

free from the effects of the vertical motion of the vehicle.



• A mechanical integrator makes cumulative measurements of the unidirectional vertical

movement of the wheel relative to the chassis.

• The distance travelled is measured by a distance measuring unit.

• The test is conducted at a speed of 32 ± 1 kmph.

• Unevenness /roughness index is defined as the ratio of the cumulative vertical

displacement to the distance travelled and is expressed in mm/km.

• The equipment is driven over the road surface at a speed of 32 ± 1 kmph, keeping steady

motion and avoiding swerving.

• The observer will activate the main switch fitted on the panel board at the beginning of

the section and switch it off at end of the section.

• The readings of the revolution counter and integrating counters are noted and entered in the

data sheet.

• The bump integrator values are recorded when the wheel revolution counter records 460

units which correspond 1 km.

• The brief description of the road surface is also noted as the observer travels over the

surface. The fifth wheel should preferably travel on wheel path.

• For measurement so roughness, one measurement in each lane is recommended for riding

comforts evaluation.

Car Mounted Bump Integrator

• The car mounted integrator consist of an integrating unit as provided in the fifth wheel

Bump Integrator.

• The integrating unit is fitted with the rear axle and mounted in the rear portion of the car or

rear floor of a jeep.

• There are two sets of counters, one each for measurement of bumps and distance along with

a switch on the panel board. Only one set of counters is used at a time. The advantage of

having two counters is that one may be kept in use while the other is kept stand-by and will

display the data of the previous run.



• In addition, the switching of the counters with the help of toggle switch provided in the

panel board gives data exactly, kilometer-wise. The power is drawn from the car itself.

• The differential movement between the rear axle and the body of the vehicle due to road

unevenness is measured by the upward vertical motion of a wire which is transmitted into

unidirectional rotary movement of the pulley of the integrator unit.

• There is an arrangement in the integrating unit for converting the rotational movement into

electric pulses which is recorded by the counters.

• One count in electromagnetic counter corresponds to 25.4 mm relative movement between

axle and floor of the vehicle & one count in distance counter corresponds to 20 m length of

distance travelled.

• The road roughness is affected by the vehicle speed. A bump gets magnified if the vehicle

speed is not maintained.

• Vehicle load is another factor which influences the roughness measurement.

• For getting the realistic values the vehicle speed must be maintained at 32 ± 1 kmph. The

laden weight of the vehicle is also standardized.

• While taking measurements the vehicle should carry maximum three passengers. It should

be ensured that the outer vehicle wheel travels on the wheel path.

INTERIOR OF CAR



MERLIN for Calibration of Bump Integrator

• MERLIN (Machine for Evaluating Road Roughness using Low Cost Instrument) is used

for calibration of Bump Integrator.

• MERLIN has a rigid frame 1.8 m long with a wheel in front, a curved foot at the rear

end and a probe mid-way between the two which rests on a road surface.

• If the road surface was perfectly smooth, the probe would always lie on straight line

between the bottom of the wheel and the rear foot.

• On an uneven road surface, the probe would usually be displaced above or below the

line.

• A computer simulation shows that the spread of these displacements could be used to

estimate on the standard roughness scale.

• To measure the displacements, the probe is attached to a pivoted arm, at the other end

of which a pointer moves over a chart. The arm has a mechanical amplification of 10 so

that a movement of the probe of 1 mm will produce a pointer movement of 10 mm.

• The roughness of a section of the road is measured by wheeling MERLIN along the road

with the framed raised. Once every wheel revolution, the frame is lowered so that the

probe and rear foot touch the ground and the resulting pointer position is recorded as a

cross on the chart.

• Two hundred measurements are made to produce a histogram. The rougher the road

surface, the greater is the viability of displacement. The speed of displacement has been

found to correlate well with road roughness as measured on roughness scale.

• The width of the central 90 % of the histogram is measured from the chart and this can

conveniently be converted directly into roughness from conversion equations that are

available.

darshan institute of engineering & technology rajkot€¦ · bm dbm sdbc bc 1 deleterious...

Documents