presentation on comparative study of concrete using recycled coarse aggregates

COMPARATIVE STUDY OF CONCRETE USING RECYCLED COARSE AGGREGATES

Project presentation on

Introduction and overviewWhat we have done so far..............................an overview

•Necessity of Recycled Coarse Aggregate•Eighth - five year plan in India investigated that there is a shortage of coarse aggregates in housing & road sectors.•In large developing countries like India, China & Japan there is a large amount of concrete & demolition waste generation due to new zoning bye laws, modified settlement patterns , increased population, in urban areas due to industrial development, modernization of old road bridges for present and future growing traffic etc.•To achieve sustainable development.•Central Pollution Control Board has estimated that the solid waste generation in India is about 48 million tonnes per annum of which 25% is from the construction industry.•Recycling of concrete is a relatively simple process. It involves breaking, removing, and crushing existing concrete into a material with a specified size and quality. •Recycled concrete aggregates contain not only the original aggregates, but also hydrated cement paste. This paste reduces the specific gravity and increases the porosity compared to similar virgin aggregates. Higher porosity of RCA leads to a higher absorption.

LITERATURE REVIEWCase studies carried out by :

Remarks

K K Sagoe-Crentsil, T Brown, A H Taylor (2001)

Water absorption rates and carbonation of recycled concrete and reference concrete were almost comparable for most applications

C S Poon, Z H Shui, L Lam, H Fok, S C Kou (2004

The result suggested that an AD aggregate that contains not more than 50% recycled aggregate is optimum for producing the normal strength recycled aggregate concrete.

Valeria Corinaldesi (2010) Results obtained showed that structural concrete can be manufactured by replacing 30% virgin aggregates with recycled concrete aggregate

Tsung – Yueh Tu, Yuen – Yuen Chen & Chao-Lung Hwang (2006)

It was found that specific gravity, water absorption capacity, gradation, soundness and wear resistance of recycled aggregate were worse than natural aggregate due to presence of residual mortar and impurities and a reduction of 20%-30% in compressive strength was noticed due to addition of recycled aggregate.

Khaldoun Rahal(2007) The trends in the development of compressive and shear strength and the strain at peak stress in recycled aggregate concrete were similar to those in natural aggregate concrete

arid Debieb, Luc Courard, Said Kenai & Robert Degeimbre (2010)

It was found that contamination of recycled aggregate does not seem to have significant effect on mechanical properties upto 28 days of age

LIST OF EXPERIMENTSExperiments performed by us :

FINE AGGREGATE EXPERIMENT

o SIEVE ANALYSIS OF FINE AGGREGATESo SILT CONTENT IN FINE AGGREGATESo BULKING OF SANDo SPECIFIC GRAVITY OF SAND

COARSE AGGREGATE EXPERIMENT

o CRUSHING VALUE OF COARSE AGGREGATESo IMPACT VALUE OF COARSE AGGREGATEo SPECIFIC GRAVITY AND WATER ABSORPTION OF COARSE AGGREGATE LARGER THAN 10MMo SIEVE ANALYSIS OF COARSE AGGREGATE.

CEMENT EXPERIMENTo NORMAL CONSISTENCY OF CEMENTo INITIAL & FINAL SETTING TIME OF CEMENTo SOUNDNESS OF CEMENTo COMPRESSIVE STRENGTH OF CEMENT

RECYCLED COARSE AGGREGATE EXPERIMENTo CRUSHING VALUE OF RECYCLED COARSE AGGREGATE o IMPACT VALUE OF RECYCLED COARSE AGGREGATEo SPECIFIC GRAVITY AND WATER ABSORPTION OF RECYCLED COARSE

AGGREGATE LARGER THAN 10MMo SIEVE ANALYSIS OF RECYCLED COARSE AGGREGATE

Experiments performed by us :LIST OF EXPERIMENTS

o SIEVE ANALYSIS OF FINE AGGREGATES

o SILT CONTENT IN FINE AGGREGATESo BUCKLING OF SAND

Experiments of Fine AggregatesSIEVE ANALYSIS OF FINE AGGREGATESApparatus: •Set of 7 sieves(10mm, 4.75mm, 2.36mm, 1.18mm, 600micron, 300micron, 150 micron ,pan) for F.M. value of coarse aggregate.•Weighing balance (5kg)•Sieve shaker

IS Sieve Size Weight Retained (Grams)

Cumulative Weight Retained (Grams)

Cumulative Percentage Weight Retained (F)

Cumulative Percentage Weight Passing

10 mm 0 0 0 04.75 mm 0 0 0 02.36 mm 58 58 5.8 94.21.18 mm 243 301 30.1 69.9600 micron 175 476 47.6 52.4300 micron 168 644 64.4 35.6150 micron 163 807 80.7 19.3

RESULT: Fineness modulus of fine Aggregate= Sum of F/100 = 228.6/100 F.M. = 2.286 Zone of Aggregate: fine aggregate ( 1st zone)

SILT CONTENT IN FINE AGGREGATES

Sample no. Silt level H1 (ml)

Sand level H2 (ml)

% of silt content (H1/H2)*100

Average % of silt content

1. 25 220 11.36 2. 30 210 14.28 11.58% 3. 20 220 9.09 4. 25 215 11.62

Apparatus:

•1000 ml glass measuring cylinder.

RESULT: Silt Content= 11.58%

BULKING OF SAND

S. no. Height of sand in containers H1 (ml)

Ht. of sand in container when container is filled with water H2 (ml)

% Bulking of sand (H1-H2/H2)* 100

1. 270 255 5.88

2. 270 240 12.5

Apparatus:•Balance, measuring cylinder 250ml capacity.

RESULT: Bulking of sand= 12.5%

SPECIFIC GRAVITY OF FINE AGGREGATE

Apparatus:•pycnometerSPECIFIC GRAVITY:W1= Weight of empty Pycnometer= 618gmW2= Weight of pycnometer with fine aggregate= 828gmW3= W2+weight of water required to fill the pycnometer= 1789gmW4= W1+weight of water required to fill the pycnometer completly= 1646gmSpecific gravity of coarse aggregate=(W2-W1)/[(W2-W1)-(W3-W4)] =(986-618)/[(986-618)-(1861-1646)] Specific gravity =2.4

Experiments of Coarse Aggregates oCRUSHING VALUE OF COARSE AGGREGATES

o IMPACT VALUE OF COARSE AGGREGATEo SPECIFIC GRAVITY AND WATER ABSORPTION OF COARSE AGGREGATE LARGER THAN 10MMo SIEVE ANALYSIS OF COARSE AGGREGATE

CRUSHING VALUE OF COARSE AGGREGATESApparatus:• Steel cylinder with open ends, and internal dia 15.2cm, square base plate plunger having a piston of dia 15 cm, with a hole provided across the stem of the plunger so that a rod could be inserted for lifting or placing the plunger in the cylinder.• Cylindrical measuring having internal dia of 11.5cm and height 18cm.• Steel temping rod with one rounded end, having a dia of 1.6cm and length 45 to60cm.• Balance of capacity 3kg with accuracy upto 1gm.• Compressions testing machine capable of applying load of 400 KN at a uniform rate of loading of 40KN/min.• IS Sieve of size 12.5mm, 10mm & 2.36mm.• Oven: a thermostatically controlled drying oven capable of maintaining constant temperature between 100 °C to 110 °C.

Sample. No.

Total weight of dry sample (W1) gm

Weight of fines passing 2.36 mm IS Sieve (W2) gm

Aggregate crushing Value = (W2/W1)*100 %

Average Aggregate crushing Value= avg. of column (4)

1. 2726 538 19.73 19.315

2. 2760 520 18.90RESULT: Aggregate crushing value= 19.315%

IMPACT VALUE OF COARSE AGGREGATE

Apparatus: Impact testing machine Tamping rod of dia 1cm and 23cm

long, rounded at one end. Sieve of size 12.5mm, 10mm &

2.36mm. Balance of capacity 3kg with

accuracy upto 1gm. Oven: a thermostatically

controlled drying oven capable of maintaining constant temperature between 100° C to 110 ° C.

Sample. No.

Total weight of dry sample (W1) gm

Weight of fines passing 2.36 mm IS Sieve (W2) gm

Aggregate Impact Value = (W2/W1)*100 %

Average Aggregate Impact Value= avg. of column (4)

1. 238 74 28.68 33.32

2. 237 90 37.97

Result: Aggregate Impact Value=33.32%

SPECIFIC GRAVITY AND WATER ABSORPTION OF COARSE AGGREGATE LARGER THAN 10MMApparatus: A balance of capacity about 3kg. to

weigh accurate to 0.5gm. A thermostatically controlled oven to

maintain temperature of 100 C to 110 C. A density basket of not more than

6.3mm mesh and it has approximate 20cm dia and 20cm height.

A container for filling water and suspending the basket.

A shallow tray and two dry absorbent clothes,each not less than 75x45cm.

SPECIFIC GRAVITY: W1= Weight of empty Pycnometer= 618gm W2= Weight of pycnometer with the coarse aggregate=

718.5gm W3= W2+weight of water required to fill the pycnometer=

1708.5gm W4= W1+weight of water required to fill the pycnometer

completly= 1647.5gm Specific gravity of coarse aggregate=(W2-W1)/[(W2-W1)-(W3-W4

=(718.5-618)/[(718.5-618)-(1708.5-1647.5)] Specific gravity =2.54

WATER ABSORPTION:

W1= Weight in grams of the saturated surface dry addregate in air= 2006gm

W2= Weight in grams of oven dried addregate in air= 1988gm

Water absorption of coarse aggregate=100(W1-W2)/W2 =100(2006-1988)/1988

Water absorption =0.905%

SIEVE ANALYSIS OF COARSE AGGREGATE

Apparatus:•Set of 11 sieves(80mm,40mm, 20mm, 10mm, 4.75mm, 2.36mm, 1.18mm, 600micron, 300 micron,150micron,pan) for F.M. value of coarse aggregate.

•Weighing balance(5 kg)

•Sieve shaker

IS Sieve Size Weight Retained (grams)

Cumulative Weight Retained (grams)



80 mm 0 0 0 0

40 mm 0 0 0 0

20 mm 0 0 0 0

10 mm 1584 1584 79.2 20.8

4.75 mm 366 1950 97.5 2.50

2.36 mm 50 2000 100 0

1.18 mm 0 2000 100 0

600 micron 0 2000 100 0

300 micron 0 2000 100 0

150 micron 0 2000 100 0

PAN 0 2000 100 0

RESULT: Fineness Modulus of coarse Aggregate= sum of F/100 = 775.7/100 F.M.= 7.757

Apparatus: Vicat’s apparatus, with plunger(10 mm dia, 50 mm height,90

gm weight) Suspended load on plunger 300 gm Vicat Mould(internal dia at lower and upper end 80mm and

70mm and height 40mm) Measuring cylinder (200ml capacity) Glass plate 12cm*12cm*4mm Trowel Weighing balance

NORMAL CONSISTENCY OF CEMENT

CEMENT EXPERIMENToNORMAL CONSISTENCY OF CEMENToINITIAL & FINAL SETTING TIME OF CEMENToSOUNDNESS OF CEMENT

RESULT: Normal Consistency of Cement = 32% by weight of dry Cement

S.NO. Weight of Cement (gm)

Percentage of water

Volume of water (ml)

Position of plunger from bottom (after penetration) (mm)

1. 400 25 100 35

2. 400 27 108 28

3. 400 30 120 17

4. 400 31 124 10

5. 400 32 128 5

INITIAL & FINAL SETTING TIME OF CEMENTFor calculation of initial & final setting time of cement weigh 400 gms of cement and prepare a cement paste with (.85P) times water required to make the paste of normal consistency.Apparatus: Vicat’s apparatus, with standard

needles(1 mm SQ) and conical ring(5 mm dia)

Vicat Mould(internal dia at lower and upper end 80mm and 70mm and height 40mm)

Measuring cylinder(200 ml capacity)

Stop watch and balance Glass plate 12cm*12cm*4mm

RESULT: Initial Setting Time of cement is found as 3 hours 10 min.

S.No. Penetration of the needle from bottom (mm)

Time (min)

1. 0 20

2. 0 40

3. 0 60

4. 0 80

5. 0 100

6. 0 120

7. 1 140

8. 1 150

9. 2 160

10. 3 170

11. 4 180

12. 5 190

FINAL SETTING TIME OF CEMENT

RESULT: Final setting time of cement is found as 5 hr. 10 min.

S.No. Impression of needle (yes/no)

Impression of annular collar (yes/no)

Time (hr. & min.)

1. yes yes 3 hr 10 min







8. yes yes 5 hr 10

min 9. yes yes 5 hr 20

min 10. yes no 5 hr 30

min

SOUNDNESS OF CEMENT

Apparatus: Le- Chatelier apparatus Glass plate Weight Balance Measuring cylinder 100 ml

capacity

For soundness, cement is gauged with .78 times the water required for standard consistency i.e. (.78P)

S.No. Initial Reading (E1) (cm)

Final Reading (E2) (cm)

Expansion (E2-E1) (cm)

1. 1.3 1.6 0.3 2. 1.2 1.6 0.4 3. 1.1 1.4 0.3

RESULT: Soundness of Cement= 0.33 cm

SPECIFIC GRAVITY OF CEMENT(OPC)Apparatus: A balance of capacity about 3kg. to weigh accurate to 0.5gm. A thermostatically controlled oven to maintain temperature of 100 C to 110

C. A density basket of not more than 6.3mm mesh and it has approximate 20cm

dia and 20cm height. A container for filling water and suspending the basket. A shallow tray and two dry absorbent clothes,each not less than 75*45cm.SPECIFIC GRAVITY: W1= Weight of empty Pycnometer= 618gmW2= Weight of pycnometer and the cement content= 828gmW3= W2+weight of water required to fill the pycnometer= 1789gmW4= W1+weight of water required to fill the pycnometer completly= 1646gm Specific gravity of coarse aggregate=(W2-W1)/[(W2-W1)-(W3-W4)] =(828-618)/[(828-618)-(1789-1646)] Specific gravity =3.13

S.NO. TYPE OF CEMENT

COMPRESSIVE STRENGTH OF CEMENT (N/mm2)

GRADE 3DAYS 7DAYS

1 OPC 43 27.28 35.1

2 OPC 43 20.86 34.8

3 OPC 43 16.85 35.35

COMPRESSIVE STRENGTH OF CEMENT

RECYCLED COARSE AGGREGATE EXPERIMENT oCRUSHING VALUE OF COARSE AGGREGATES

o IMPACT VALUE OF COARSE AGGREGATEo SPECIFIC GRAVITY AND WATER ABSORPTION OF COARSE AGGREGATE LARGER THAN 10MMo SIEVE ANALYSIS OF COARSE AGGREGATE

CRUSHING VALUE OF RECYCLED COARSE AGGREGATE Apparatus:•Steel cylinder with open ends, and internal dia 15.2cm, square base plate plunger having a piston of dia 15 cm, with a hole provided across the stem of the plunger so that a rod could be inserted for lifting or placing the plunger in the cylinder.•Cylindrical measuring having internal dia of 11.5cm and height 18cm.•Steel temping rod with one rounded end, having a dia of 1.6cm and length 45 to 60cm.•Balance of capacity 3kg with accuracy upto 1gm.•Compressions testing machine capable of applying load of 400 KN at a uniform rate of loading of 40KN/min.•IS Sieve of size 12.5mm, 10mm & 2.36mm.•Oven: a thermostatically controlled drying oven capable of maintaining constant temperature between 100 C to 110 C.

Sample No. Total Weight of Dry Sample (W1) (gm)

Weight of fines passing 2.36 mm IS Sieve (W2) (gm)

Aggregate Crushing Value= (W2/W1)*100 %

Avg. aggregate crushing value= Average of column (4)

1. 2318 657 28.44 28.28

2. 2310 650 28.13

RESULT: Aggregate Crushing Value= 28.28%

IMPACT VALUE OF RECYCLED COARSE AGGREGATEApparatus: Impact testing machine Tamping rod of dia 1cm and 23cm long, rounded at one end. Sieve of size 12.5mm, 10mm & 2.36mm. Balance of capacity 3kg with accuracy upto 1gm. Oven: a thermostatically controlled drying oven capable of

maintaining constant temperature between 100 C to 110 C.

Sample No. Total Weight of Dry Sample (W1) (gm)

Weight of fines passing 2.36 mm IS Sieve (W2) (gm)

Aggregate Impact Value= (W2/W1)*100 %

Avg. aggregate Impact value= Average of column (4)

1. 218 77 35 31

2. 285 77 27.01

RESULT: Aggregate Impact Value= 31%

SPECIFIC GRAVITY AND WATER ABSORPTION OF RECYCLED COARSE AGGREGATE LARGER THAN 10MMApparatus: A balance of capacity about 3kg. to weigh accurate to 0.5gm. A thermostatically controlled oven to maintain temperature of 100 C to

110 C. A density basket of not more than 6.3mm mesh and it has

approximate 20cm dia and 20cm height. A container for filling water and suspending the basket. A shallow tray and two dry absorbent clothes,each not less than

75*45cm.

SPECIFIC GRAVITY: W1= Weight of empty Pycnometer= 618gmW2= Weight of pycnometer with recycled coarse aggregate= 778.5gmW3= W2+weight of water required to fill the pycnometer= 1700gmW4= W1+weight of water required to fill the pycnometer completly=

1647.5gm Specific gravity of coarse aggregate=(W2-W1)/[(W2-W1)-(W3-W4)] =(778.5-618)/[(778.5-618)-(1700-

1647.5)] Specific gravity =1.48WATER ABSORPTION: W1= Weight in grams of the saturated surface dry addregate in air=

2100gmW2= Weight in grams of oven dried addregate in air= 1941gm Water absorption of coarse aggregate=100(W1-W2)/W2 =100(2100-1941)/1941 Water absorption =8.19%

SIEVE ANALYSIS OF RECYCLED COARSE AGGREGATE

Apparatus: Set of 11 sieves(80mm,40mm, 20mm, 10mm,

4.75mm, 2.36mm, 1.18mm, 600micron, 300 micron,150micron,pan)

Weighing balance Sieve shaker

RESULT: Fineness Modulus of Recycled Coarse Aggregate= Sum of F/100 = 790.35/100 F.M. = 7.90

IS Sieve Size Weight Retained (gm)

Cumulative Weight Retained (gm)



80 mm 0 0 0 0

40 mm 0 0 0 0

20 mm 29 29 1.45 98.55

10 mm 1750 1779 88.95 11.05

4.75 mm 220 1999 99.95 0.05

2.36 mm 1 2000 100 0

1.18 mm 0 2000 100 0

600 micron 0 2000 100 0

300 micron 0 2000 100 0

150 micron 0 2000 100 0

PAN 0 2000 100 0

MIX Design for M25 Concrete USING FRESH COARSE AGGREGATE (IS 10262-1982)(MIX A)To do mix design for M25Cement used- OPC 43 gradea) (fck)28 days = 25 N/mm2 (MPa)

b) workability (medium slump) we know that, ft=fck+t*s Where, ft= target average compressive strength at 28

days fck= characteristic compressive strength at 28

days s= standard deviation t= a statistic, depending upon the accepted

proportion of low results and the number of tests(value should be taken from table no.2 of IS 10262-1982)

Now taking t=1.65 (as per IS 456-1978 and IS 1343-1980, the characteristic strength is defined as that value below which not more than 5 percent (1 in 20) results are expected to fall. In such case, the above equation will reduce to: Ft=Fck+1.65snow, s=5.3 for M25 Good quality control Ft=33.745 N/mm2for water cement ratio=0.42 as per figure 1 of IS 10262-1982now,28 days cement compressive strength= 53 N/mm2for water cement ratio=0.475 as per figure 2 of IS 10262-1982design for normal concrete using normal coarse aggregate1) air content- for MAS 20mm= 2%

MAS water content per cubic meter of concrete

sand as percent of total aggregate by absolute volume

20 186 35

For M25 concrete, fine aggregate zone 2, water-cement ratio-0.6compact factor- 0.8now taking the workability- medium-slump value= 50 to 100compaction factor= 0.92 (ref. MS Shetty page no. 225)now taking the condition as moderate-design for reinforced concrete min. cement content= 400 kg/m3 (300)max. water- cement ratio= 0.5 (taken 0.475 for M25)Adjustment of values in water content and sand percentage for other conditions

change adjustment required in (1) Water

content (2)

Percentage, sand in total aggregate (3)

Decrease in w/c ratio(0.6-0.475)=0.125

0 -3.0

Increase in compacting factor (0.92-0.8)=0.12

+3.0 0

Sand conforming to zone 1

0 +1.5

+3.0 -1.5

Required sand content as a % of total aggregate by absolute volume=35-1.5=33.5%required water content,V=186+(186*3/100) V=191.61 kg/m3 determination of cement content,w/c ratio=0.475water=191.61 kg/m3cement= 191.61/0.475=403.368 kg/m3 (>300 kg/m3)Required sand content as a % of total aggregate by absolute volume=35-1.5=33.5%required water content,V=186+(186*3/100) V=191.61 kg/m3determination of cement content,w/c ratio=0.475water=191.61 kg/m3cement= 191.61/0.475=403.368 kg/m3 (>300 kg/m3)

determination of coarse and fine aggregatefine aggregate:

0.98=[191.61+(403.368/3.164)+{(1/0.335)*(fa/2.4183)}]/100fa=535.426 kg/m3coarse aggregate:

0.98=[191.61+(403.368/3.164)+{(1/0.665)*(Ca/2.54)}]/100 Ca=1116.3486 kg/m3the mix proportion then become:-water=191.6 kgcement=403.368 kgsand=535.426 kgcoarse aggregate=1116.3486 kg

Then,ratio of actual quantities required for mix per beg of cement,water:cement:sand:coarse aggregate=0.475:1:1.3273:2.767now for 50 kg cement;sand=66.365 kgcoarse aggregate=138.35 kga) water=23.75 letersb) extra water to be added for absord by coarse aggregate taking @ 0.90% by mass=(.90/100)*138.35 =1.245(+)c) quqntity of water to be deducted for free moisture present in the sand, 1% by mass=(1/100)*66.365 =0.66365actual quantity of water to be added=23.75+1.245-0.66365 =24.33135 litersactual quantity of sand required after absorbing the free moisture=66.365+0.66365 =67.02865 kg

actual mix constituents for 1 beg of cement; water=24.33 leterscement=50 kgsand=67.028 kgcoarse aggregate=137.105 kgfor 1 cube ratio of the constituents are 0.486:1:1.3405:2.742for 9 cubes ratio of the consitituents are6.804:14:18.767:38.388

MIX Design for M25 Concrete USING RECYCLED COARSE AGGREGATE (IS 10262-1982) (MIX B)

To do mix design for M25 Cement used- OPC 43 grade(fck)28 days = 25 N/mm2 (MPa)workability (medium slump)we know that, ft=fck+t*s Where, ft= target average compressive strength at 28 days fck= characteristic compressive strength at 28 days s= standard deviation t= a statistic, depending upon the accepted proportion of low results

and the number of tests(value should be taken from table no.2 of IS 10262-1982)

Now taking t=1.65 (as per IS 456-1978 and IS 1343-1980, the characteristic strength is defined as that value below which not more than 5 percent (1 in 20) results are expected to fall. In such case, the above equation will reduce to:

Ft=Fck+1.65snow,

s=5.3 for M25 Good quality control Ft=33.745 N/mm2for water cement ratio=0.42 as per figure 1 of IS 10262-1982now,28 days cement compressive strength= 53 N/mm2for water cement ratio=0.475 as per figure 2 of IS 10262-1982design for normal concrete using normal coarse aggregate1) air content- for MAS 40mm= 1%



40 165 30

For M25 concrete, fine aggregate zone 2, water-cement ratio-0.6compact factor- 0.8now taking the workability- medium-slump value= 50 to 100compaction factor= 0.92 (ref. MS Shetty page no. 225)now taking the condition as moderate-design for reinforced concrete min. cement content= 300 kg/m3 max. water- cement ratio= 0.5 (taken 0.475 for M25)

Adjustment of values in water content and sand percentage for other conditions

change adjustment required in (1) Water content

(2) Percentage, sand in total aggregate (3)


0 -3.0


+3.0 0


0 +1.5

+3.0 -1.5

Required sand content as a % of total aggregate by absolute volume=30-1.5=28.5%required water content,V=165+(165*3/100) V=169.95 kg/m3

V=170 kg/m3determination of cement content,w/c ratio=0.475water=170kg/m3cement= 170/0.475=357.89 kg/m3 (>300 kg/m3)

= 358 kg/m3 determination of coarse and fine aggregate

fine aggregate: 1-0.01=0.99=[170+(358/3.164)+{(1/0.285)*(fa/2.41)}]/1000

fa=483.486 kg/m3coarse aggregate:

0.99=[170+(368/3.164)+{(1/0.715)*(Ca/2.54)}]/1000Ca=1283.64 kg/m3the mix proportion then become:-water=170 kgcement=358 kgsand=483.486 kgcoarse aggregate=1283.64 kg

Then,ratio of actual quantities required for mix per beg of cement,water:cement:sand:coarse aggregate=0.475:1:1.35:3.585now for 50 kg cement;sand=67.5 kgcoarse aggregate=179.25 kgwater=23.75 letersextra water to be added for absord by recycled coarse aggregate taking @ 8.19% by mass=(8.19/100)*179.25 =14.68(+)quantity of water to be deducted for free moisture present in the sand, 1% by mass=(1/100)*67.5 =0.675(-)

actual quantity of water to be added=23.75+14.68-0.675 =37.755 litersactual quantity of sand required after absorbing the free moisture=67.5+0.675 =68.175 kg

Actual quantity of recycled coarse aggregate required=179.25-14.68=164.57kgactual mix constituents for 1 beg of cement; water=37.755 leterscement=50 kgsand=68.175 kgcoarse aggregate=164.57 kgfor 1 cube ratio of the constituents are 0.755:1:1.363:3.2914for 9 cubes ratio of the consitituents are10.57:14:19.082:46.06

MIX Design for M25 Concrete USING RIVER SAND AND STONE DUST AS SAND FOR NORMAL COARSE AGGREGATE (IS 10262-1982) (MIX C) To do mix design for M25 Cement used- OPC 43 grade (fck)28 days = 25 N/mm2 (MPa) b) workability (medium slump) we know that, ft=fck+t*s Where, ft= target average compressive strength at 28 days fck= characteristic compressive strength at 28 days s= standard deviation t= a statistic, depending upon the accepted proportion of low

results and the number of tests(value should be taken from table no.2 of IS 10262-1982)

Now taking t=1.65 (as per IS 456-1978 and IS 1343-1980, the characteristic strength is defined as that value below which not more than 5 percent (1 in 20) results are expected to fall. In such case, the above equation will reduce to:

Ft=Fck+1.65snow, s=5.3 for M25 Good quality control Ft=33.745 N/mm2for water cement ratio=0.42 as per figure 1 of IS 10262-1982now,28 days cement compressive strength= 53 N/mm2for water cement ratio=0.475 as per figure 2 of IS 10262-1982design for normal concrete using normal coarse aggregate1) air content- for MAS 20mm= 2%



20 186 35

For M25 concrete, fine aggregate zone 2, water-cement ratio-0.6compact factor- 0.8now taking the workability- medium-slump value= 50 to 100compaction factor= 0.92 (ref. MS Shetty page no. 225)now taking the condition as moderate-design for reinforced concrete min. cement content= 300 kg/m3 max. water- cement ratio= 0.5 (taken 0.475 for M25)

Adjustment of values in water content and sand percentage for other conditions

change adjustment required in

(1) Water content (2)



0 -3.0


+3.0 0


0 -3.0

+3.0 -6

Required sand content as a % of total aggregate by absolute volume=35-6=29%required water content,V=186+(186*3/100) V=191.6 kg/m3

determination of cement content,w/c ratio=0.475water=191.6kg/m3cement= 191.6/0.475=403.368 kg/m3 (>300 kg/m3)


1-0.02=0.98=[191.6+(403.37/3.164)+{(1/0.29)*(fa/2.58)}]/1000fa=494.36 kg/m3coarse aggregate:

0.98=[191.6+(403.37/3.164)+{(1/0.71)*(Ca/2.54)}]/1000Ca=1191.9 kg/m3the mix proportion then become:-

water=191.6 kgcement=403.368 kgsand=494.36 kgcoarse aggregate=1191.9 kg

Then,ratio of actual quantities required for mix per beg of cement,water:cement:sand:coarse aggregate=0.475:1:1.2255:2.955now for 50 kg cement;sand=61.275 kgcoarse aggregate=147.75 kgwater=23.75 letersextra water to be added for absord by normal coarse aggregate taking @ 0.90% by mass=(.90/100)*147.75 =1.33(+)quantity of water to be deducted for free moisture present in the sand, 1% by mass=(1/100)*61.275 =0.612(-)actual quantity of water to be added=23.75+1.33-0.612 =24.47 litersactual quantity of sand required after absorbing the free moisture=61.275+0.612 =61.89 kg

Actual quantity of coarse aggregate required=147.75-1.33=146.42 kgactual mix constituents for 1 beg of cement; water=24.47 leterscement=50 kgsand=61.89 kgcoarse aggregate=146.42 kgfor 1 cube ratio of the constituents are 0.489:1:1.238:2.93for 9 cubes ratio of the consitituents are6.846:14:17.332:41.02

MIX Design for M25 Concrete USING RIVER SAND AND STONE DUST AS SAND FOR RECYCLED COARSE AGGREGATE (IS 10262-1982) (MIX D) To do mix design for M25 Cement used- OPC 43 grade (fck)28 days = 25 N/mm2 (MPa) b) workability (medium slump) we know that, ft=fck+t*s Where, ft= target average compressive

strength at 28 days fck= characteristic compressive

strength at 28 days s= standard deviation

t= a statistic, depending upon the accepted proportion of low results and the number of tests(value should be taken from table no.2 of IS 10262-1982)

Now taking t=1.65 (as per IS 456-1978 and IS 1343-1980, the characteristic strength is defined as that value below which not more than 5 percent (1 in 20) results are expected to fall. In such case, the above equation will reduce to: Ft=Fck+1.65snow, s=5.3 for M25 Good quality control Ft=33.745 N/mm2for water cement ratio=0.42 as per figure 1 of IS 10262-1982now,28 days cement compressive strength= 53 N/mm2for water cement ratio=0.475 as per figure 2 of IS 10262-1982design for normal concrete using normal coarse aggregate

1) air content- for MAS 20mm= 2%



20 186 35

For M25 concrete, fine aggregate zone 2, water-cement ratio-0.6compact factor- 0.8now taking the workability- medium-slump value= 50 to 100compaction factor= 0.92 (ref. MS Shetty page no. 225)now taking the condition as moderate-design for reinforced concrete min. cement content= 300 kg/m3 max. water- cement ratio= 0.5 (taken 0.475 for M25)Adjustment of values in water content and sand percentage for other conditions





0 -3.0


+3.0 0


0 -3.0

+3.0 -6

Required sand content as a % of total aggregate by absolute volume=35-6=29%required water content,V=186+(186*3/100) V=191.6 kg/m3

determination of cement content,w/c ratio=0.475water=191.6kg/m3cement= 191.6/0.475=403.368 kg/m3 (>300 kg/m3)





Then,ratio of actual quantities required for mix per beg of cement,water:cement:sand:coarse aggregate=0.475:1:1.2255:2.955now for 50 kg cement;sand=61.275 kgcoarse aggregate=147.75 kgwater=23.75 letersextra water to be added for absord by recycled coarse aggregate taking @ 8.19% by mass=(8.19/100)*147.75 =12.09(+)quantity of water to be deducted for free moisture present in the sand, 1% by mass=(1/100)*61.275 =0.612(-)

actual quantity of water to be added=23.75+12.09-0.612 =35.227 litersactual quantity of sand required after absorbing the free moisture=61.275+0.612 =61.89 kg


MIX Design for M25 Concrete USING RIVER SAND AND STONE DUST AS SAND AND PPC CEMENT FOR NORMAL COARSE AGGREGATE (IS 10262-1982) (MIX E) To do mix design for M25 Cement used- PPC (fck)28 days = 25 N/mm2 (MPa) b) workability (medium slump) we know that, ft=fck+t*s Where, ft= target average compressive strength at 28 days fck= characteristic compressive strength at 28 days s= standard deviation t= a statistic, depending upon the accepted




20 186 35






0 -4.0


+3.0 0


0 -3.0

+3.0 -7.0

Required sand content as a % of total aggregate by absolute volume=35-7=28%required water content,V=186+(186*3/100) V=191.6 kg/m3 determination of cement content,w/c ratio=0.42water=191.6kg/m3cement= 191.6/0.42=456.2 kg/m3 (>300 kg/m3)


Then,ratio of actual quantities required for mix per beg of cement,water:cement:sand:coarse aggregate=0.42:1:1.019:2.57now for 50 kg cement;sand=50.95 kgcoarse aggregate=128.5 kgwater=21 letersextra water to be added for absord by normal coarse aggregate taking @ 0.90% by mass=(.90/100)*128.5 =1.156(+)

quantity of water to be deducted for free moisture present in the sand, 1% by mass=(1/100)*50.95 =0.50(-)actual quantity of water to be added=21+1.156-0.50 =21.656 litersactual quantity of sand required after absorbing the free moisture=50.95+.50 =51.45 kg


MIX Design for M25 Concrete USING RIVER SAND AND STONE DUST AS SAND AND PPC CEMENT FOR RECYCLED COARSE AGGREGATE (IS 10262-1982) (MIX F) To do mix design for M25 Cement used- PPC (fck)28 days = 25 N/mm2 (MPa) b) workability (medium slump) we know that, ft=fck+t*s Where, ft= target average compressive strength at 28 days fck= characteristic compressive strength at 28 days s= standard deviation t= a statistic, depending upon the accepted




20 186 35






0 -4.0


+3.0 0

Sand conforming to zone 4 0 -3.0

+3.0 -7.0

Required sand content as a % of total aggregate by absolute volume=35-7=28%required water content,V=186+(186*3/100) V=191.6 kg/m3 determination of cement content,w/c ratio=0.42water=191.6kg/m3cement= 191.6/0.42=456.2 kg/m3 (>300 kg/m3)


1-0.02= 0.98=[191.6+(456.2/3.15)+{(1/0.28)*(fa/2.58)}]/1000fa=464.92 kg/m3coarse aggregate:



Then,ratio of actual quantities required for mix per beg of cement,water:cement:sand:coarse aggregate=0.42:1:1.019:2.57now for 50 kg cement;sand=50.95 kgcoarse aggregate=128.5 kgwater=21 letersextra water to be added for absord by recycled coarse aggregate taking @ 8.19% by mass=(8.19/100)*128.5 =10.52(+)

quantity of water to be deducted for free moisture present in the sand, 1% by mass=(1/100)*50.95 =0.50(-)actual quantity of water to be added=21+10.52-0.50 =31.01 litersactual quantity of sand required after absorbing the free moisture=50.95+.50 =51.45 kg

Actual quantity of recycled coarse aggregate required=128.5-10.52=117.98 kgactual mix constituents for 1 beg of cement; water=31.01leterscement=50 kgsand=51.45 kgcoarse aggregate=117.98 kgfor 1 cube ratio of the constituents are 0.6202:1:1.029:2.3596for 9 cubes ratio of the consitituents are8.683:14:14.406:33.0344

RESULTS

Compressive strength at different stages by using natural aggregate

S NO. Concrete containing ingredients

7 days (N/mm2)

28 days (N/mm2)

1 MIX A 27.22 35.002 MIX C 27.663 MIX E 25.55

Compressive strength at different stages by using recycled aggregate

S NO. Concrete containing ingredients

7 days (N/mm2)

28 days

(N/mm2)

1 MIX B 24.88 31.612 MIX D 21.383 MIX F 20.88

CONCLUSION

The strength of concrete using OPC with fresh coarse aggregate in general increses slitely when the equal proportion of river sand & stone dust are used in place of sand.

While the strength of concrete using PPC with fresh coarse aggregate in general decreases when the equal proportion of river sand & stone dust are used in place of sand.

The strength of concrete using OPC with recycled coarse aggregate in general decreases when the equal proportion of river sand & stone dust are used in place of sand.

While the strength of concrete using PPC with recycled coarse aggregate in general decreases when the equal proportion of river sand & stone dust are used in place of sand.

Preeti Gangwar Siddharth SharmaShanu AggarwalPrateek JhanjiSaptrishi MandalVaibhav Srivastav

Presented By :

presentation on comparative study of concrete using recycled coarse aggregates

Engineering