summer research report

SUMMER RESEARCH REPORT

FRESH AND HARDENED CHARACTERISTICS OF

NORMAL STRENGTH SELF-COMPACTING

CONCRETE

May 15th 2015 – July 15th 2015

Prepared by

ADITYA S BAJAJ

B.TECH CIVIL ENGINEERING

VJTI, MUMBAI

Guided by

DR. BHUPINDER SINGH

ASSOCIATE PROFESSOR

DEPT. OF CIVIL ENGINEERING

Department of Civil Engineering

INDIAN INSTITUTE OF TECHNOLOGY ROORKEE

ROORKEE-247667, UTTARAKHAND, INDIA

Summer Research Report-Fresh and Hardened Characteristics of Normal Strength SCC

1 Department of Civil Engineering, IIT Roorkee.

CANDIDATE’S DECLARATION

I hereby declare that the work presented in this dissertation entitled “Fresh and

Hardened Characteristics of Normal Strength Self-Compacting Concrete” has been carried

out by me in partial fulfilment of the requirements for the Summer Research Training at the Civil

Engineering Department, Indian Institute of Technology Roorkee. This report is an authentic

record of my own work carried out in the period from May 2015 to July 2015 under the

supervision of Dr.Bhupinder Singh, Associate Professor, Department of Civil Engineering,

Indian Institute of Technology Roorkee. Matter presented in this report has not been submitted

for the award of any degree.

Place: Roorkee

Date:

Aditya S. Bajaj



CERTIFICATE

This is to certify that Aditya S. Bajaj of Veermata Jijabai Technological Institute (V.J.T.I),

Mumbai, has successfully completed his summer training from 15.05.2015 to 15.07.2015 at

Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee on “Fresh

and Hardeened Characteristics of Normal Strength Self Compacting Concrete” submitted

by him to the undersigned. It is an authentic record of his original work, which he has carried out

under my supervision and guidance.

I wish him all the very best.

Date:

Dr. Bhupinder Singh

Associate Professor

Department of Civil Engineering

Indian Institute of Technology Roorkee

Roorkee – 247667

Uttarakhand, India



ACKNOWLEDGEMENT

First of all, I praise God, the almighty, merciful and passionate, for providing me this

opportunity and granting me the capability to proceed successfully.

I would like to take this opportunity to express my profound gratitude and deep regards to

my guide Dr. Bhupinder Singh,Associate Professor, Civil Engineering Department, Indian

Institute of Technology Roorkee, for his valuable guidance, feedback and generosity throughout

the duration of the project. His valuable suggestions were of immense help throughout my

project work. I thank him for always being available in spite of his busy schedule.

Dr. Bhupinder Singh has truly been awe-inspiring and working under him was a

completely new and highly educating experience for me.

.

I would also like to thank Dr. P.P. Bhave, Associate Professor and Head, Civil and

Environmental Engineering Department, Veermata Jijabai Technological Institute (V.J.T.I),

Mumbai for giving me the permission and opportunity to work for this summer internship

project. I extend my sincerest gratitude to Dr. Sandeep S. Pendhari, Associate Professor,

Structural Engineering Department, V.J.T.I., Mumbai for recommending and encouraging me to

pursue this training.

I thank Mr. Subhash B. Gurram, Scientist, CBRI Roorkee, Ajit Saini, Research Assistant,

Rajdeep Maurya, MTech 1st Year and Mr. Shakeel Waseem, Ph.D student, Structural Dynamics,

IITR for their continuous assistance and help during the project.

Finally, I thank the Lab incharge and all supporting staff of the Casting and Materials

testing laboratory, Structural Engineering Department, IIT Roorkee.

Aditya S. Bajaj



TABLE OF CONTENTS

Candidate Declaration ............................................................................................................... 1

Certificate ................................................................................................................................. 2

Acknowledgement .................................................................................................................... 3

Table of Contents...................................................................................................................... 4

1. CHAPTER 1 ....................................................................................................................... 6

1.1. Abstract ....................................................................................................................... 6

1.2. Introduction ................................................................................................................. 6

1.2.1 Advantages of SCC………………………………………………………………. 6

1.3. Experimental Program…………………………………………………………………. 7

2. CHAPTER 2…………………………………………………………………………………8

2.1. Cement…………………………………………………………………………………....8

2.2. Fly Ash……………………………………………………………………………………8

2.3. Fine Aggregate……………………………………………………………………………9

2.4. Coarse Aggregate…………………………………………………………………………9

2.5. Water…………………………………………………………………………………….10

2.6. Super plasticizer…………………………………………………………………………10

2.7. Viscosity Modifying Admixture (VMA) ……………………………………………….10

3. CHAPTER 3…………………………………………………………………………………11

3.1. Requirements……………………………………………………………………………11

3.2. Workability and Acceptance Criterion………………………………………………….11

3.3. Test Methods…………………………………………………………………………....12

3.3.1. Slump Flow and T50……………………………………………………………..12

3.3.2. V-Funnel and V-Funnel 5Minutes……………………………………………….13

3.3.3. L-Box Test……………………………………………………………………….15

3.3.4. U-Box Test……………………………………………………………………….16

3.3.5. J-Ring Test……………………………………………………………………….18

4. CHAPTER 4…………………………………………………………………………………20

4.1. SCC Mix Design………………………………………………………………………...20

4.2. Selection of Mix Proportion…………………………………………………………….20

4.3. Mix Proportions and Trials……………………………………………………………...20

4.3.1. The V-Funnel Complication……………………………………………………..21

4.3.2. The V-Funnel Solution…………………………………………………………..21

5. CHAPTER 5…………………………………………………………………………………25

5.1. Hardened Characteristics………………………………………………………………..25



5.2. Normal Strength Mix……………………………………………………..……………..25

5.3. 7-Days Cube Compressive Strength………………………………………………….....25

5.4. 14-Days Cube Compressive Strength……………………………………………….…..26

5.5. 14-Days Split Tensile Strength………………………………………………………….26

5.6. 14-Days Flexural Strength (Modulus of Rupture) ……………………………………..29

5.7. 14-Days Stress-Strain Analysis…………………………………………………………30

5.7.1. Stress V/S Percentage Strain Curves…………………………………………... 30

5.8. Hardened Properties Discussion………………………………………………………. 32

6. CHAPTER 6………………………………………………………………………………...33

6.1. Concrete Rheology……………………………………………………………………..33

6.2. The Bingham Model……………………………………………………………………33

7. CONCLUSION……………………………………………………………………………..36

8. REFERENCES……………………………………………………………………………..37

9. APPENDIX…………………………………………………………………………………38

1. Application to program and Consent letter from Parent Institute…………………..38

2. Approval Letter from IIT Roorkee………………………………………………….39



CHAPTER 1

1.1 Abstract

The research study presented in this report aims to establish a reliable mix design for

normal strength self-compacting concrete. Subsequently, it also tends to investigate some of

the essential fresh properties of self-compacting concrete that distinguish it from

conventionally vibrated concrete. Finally, the report states the result of certain characteristic

hardened properties of the finalized mix design.

Self-consolidating or Self-Compacting concrete, abbreviated as SCC, may be one of the

most significant concrete technology developments in many years. Because of its

characteristic fresh properties, it has the potential to dramatically alter and improve the

future of concrete placement and construction processes. The use of SCC may lead to labor

and construction time savings and result in far better architectural finishes. The primary

difference between SCC and conventional concrete is in their fresh properties. Much

research has been conducted and the industry understand of SCC has developed since its

inception. There are certainly some new developments needed to further improve its

applications.

1.2 Introduction

SCC is defined as concrete that “can be compacted into every corner of a formwork, purely

by means of its own weight and without the need for vibratory compaction”. SCC is a highly

flowable concrete that can spread easily under its own weight without segregation and

blockage. Such a concrete is used to ensure the filling of the spaces between heavily

congested reinforced sections and in areas with restricted access to vibration. It is also

employed to improve the productivity of the concrete placement, as well as improve site

working condition as it ensures noise reduction by eliminating vibration consolidation. Self

Compacting Concrete is presently being used only as a special concrete by large

construction company because of stringent requirements of quality control in its mixture

proportioning. SCC is an extension of existing concrete technology and typically uses the

same materials as conventional concrete. The primary difference between SCC and

Conventional Concrete is in their fresh property targets.

1.2.1 Advantages of SCC SCC which is properly proportioned and placed has both economic and technological benefit to

the end user. SCC can provide the following benefits:

Reduce labor and equipment: o No need for vibration to ensure proper consolidation. This also results in

savings in equipment purchasing and their maintenance & operation.



o Less need for screeding operations to ensure flat surfaces.

More rapid placement of concrete and accelerated construction.

Ease of placement and consolidation in difficult situations owing to access

limitations or configuration of element formwork and reinforcement.

Expanded use of concrete in architecturally challenging applications.

Reductions in equipment needs such as vibrators, concrete pumps.

Shortened concrete delivery times.

Improved surface finish.

Reduced patching labor and materials.

Improved working conditions for laborers, potentially resulting in :

o Improved employee retention

o Reduced employee absence

Improved Safety

o Fewer workers on the walls needed for placement and consolidation.

o Fewer electrical and air lines running across the plant floors for vibration

o Less noise

All these have potential to result in:

o Fewer injuries and resulting lost time.

o Reduced workers compensation claims.

o Reduced insurance Premium.

Therefore, it can be said that SCC is a technology that provides both cost savings and

expanded performance benefits.

1.3 Experimental Program

The experimental program was carried out in the following stages:

a. Materials Property Testing

b. Batching Trial Mixes

c. Investigating Fresh Properties

d. Modifying Trial Mixes based on observations

e. Investigating Hardened Properties

In addition to proportioning normal strength mix design, trials were simultaneously carried out

on medium strength SCC mixtures as well.



CHAPTER 2

Materials

The experimental work was initiated with characterization of the locally available materials in

Roorkee routinely used for the making of concrete. The measured physical properties of these

materials and the details of the empirically developed SCC mixtures are discussed in the

following sections.

2.1 Cement 43 Grade Ordinary Portland Cement (OPC 43) from a single source was used and the

physical properties of the cement which conformed to Indian Standard IS 8112: 1989 are listed

in Table 1.

Table 2.1: Physical properties of Cement (OPC Grade 43)

Charactersitic Result

IS 8112:1989 Requirement

Blaines Fineness (cm2/gm) 2776.08 >2250

Specific Gravity 3.16 3.14

Soundness-Le Chatelier's test (mm) 2 <10

Autoclave expansion(%) 0.07 <0.8

Normal Consistency (%of Cement by weight) 29 30

Intitial Setting Time(mins) 30 >30

Final Setting Time(mins) 180 <600

Compressive Strength (Mpa) 3-days 23.02 >23

7-days 30 >33

2.2 Fly-ash A low-calcium fly ash obtained from the combined fields of the electrostatic precipitator

of the thermal power plant at Dadri, India was used. The physical and chemical characteristics of

the fly ash is given in Table 2 satisfy the requirements of IS 3812: 1981.



Table 2.2: Physical & Chemical Properties of FlyAsh

Property Measurement

Blaines Fineness (cm2/gm) 3477

Specific Gravity 2.24

Silicon dioxide, SiO2, (%by mass) 51.4

SiO2 + Al2O3 + Fe2O3 , (by mass) 91

Loss on Ignition, (%by Mass) 0.6

2.3 Fine aggregate The physical properties of the fine aggregate are listed in Tables 3. The fine aggregate

confirmed to Zone III of IS 383: 1970.

Table 2. 3: Physical properties of the Fine Aggregate

Characteristic Result

Grading Zone III (IS:383-1970)


Fineness Modulus 2.5

Density (Loose) kN/m3 15.5

Water Absorption (%) 2.04

Moisture Content (%) 0.45

2.4 Coarse aggregate Locally available crushed stone aggregate of 12.5 mm nominal maximum size and having

a specific gravity of 2.70 was used as the coarse aggregate in the SCC mixtures. Physical

properties of the aggregates are given in Table 5.

The Fig.1 shows the Particle size distribution of the coarse and fine aggregates used from

storage bin. The coarse aggregates used were specifically in the size range of 10mm to 12.5mm.

Table 2.4: Physical Properties of Coarse Aggregate (Nominal size <16mm)

Characteristic Result

Fineness modulus 7.27


Dry Rodded Bulk density (kg/m3) 1596.667

Water Absorption 0.81

Moisture Content (%) Nil



Fig 2.1: Gradation Curve for Coarse and Fine Aggregate

2.5 Water Potable tap water which was free of any deleterious materials is used for both mixing and

curing of concrete.

2.6 Superplasticizer A commercially available super plasticizer (Glenium 51) based on modified

polycarboxylic ether and conforming to ASTM C 494 Types A and F and IS 9103: 1999 with a

specific gravity of 1.05 was used as the high range water reducing admixture in the SCC

mixtures. The molecular configuration of the super plasticizer accelerates hydration of cement.

Rapid adsorption of the molecules onto the cement particles, combined with an efficient

dispersion effect, exposes an increased surface of the cement grains to reaction with water.

2.7 Viscosity Modifying Admixture (VMA) MasterMatrix VMA 362 viscosity-modifying admixture (VMA), a ready-to-use, liquid

admixture that is specially developed for producing concrete with enhanced viscosity and

controlled rheological properties, was used. Concrete containing MasterMatrix VMA 362

admixture exhibits superior stability, thus increasing resistance to segregation and facilitating

placement and consolidation. MasterMatrix VMA 362 admixture meets ASTM C 494/C 494M

requirements for Type S, Specific Performance, admixtures. The VMA had a specific gravity of

0.98.

020

4060

8010

0

0.1 1 10 100

% F

ine

r Th

an

Particle Size (mm)

FineAggregate

CoarseAggregate



CHAPTER 3

This chapter briefly describes the desired performance criteria for fresh SCC mixture. It enlists

the basic requirements of the concrete mix and the test methods used to establish the fresh

properties and parameters.

3.1 Requirements SCC can be designed to fulfill the requirements regarding density, strength development, final

strength and durability.

Due to the high content of powder, SCC may show more plastic shrinkage or creep than ordinary

Concrete mixes. These aspects should therefore be considered during designing and specifying

SCC. Current knowledge of these aspects is limited and this is an area requiring further research.

Special care should also be taken to begin curing the concrete as early as possible.

The workability of SCC is higher than the highest class of consistence described within EN 206

and can be characterized by the following properties:

Filling ability: It is the ability of the fresh concrete mixture to flow into and fill formwork under

its own weight. This term is often used interchangeably with fluidity and flow as they pertain to

SCC. For a mixture to be considered SCC, it must have adequate filling ability.

Passing ability: It is the ability of SCC mixture to flow through restricted spaces without

blocking. This property is generally concerned with aggregate flowing through dense

reinforcement; however, it can also refer to flow through narrowing sections in formwork or

when reducers are present on concrete pipelines. Any situation where the concrete particles have

to rearrange themselves in order to flow through an obstacle is where passing ability

characteristics are important.

Segregation resistance: It is the ability of an SCC mixture to resist segregation of its constituent

materials. Stability is defined under two conditions: dynamic and static. Dynamic stability refers

to the segregation resistance of the mix during transport, placement and up to the point where

static stability takes over. Techniques for improving the dynamic stability of SCC include

reducing the slump flow level and reducing the coarse aggregate size and density. Static stability

refers to the ability of the mixture constituents to resist segregation and settlement as the

concrete sits undisturbed.

A concrete mix can only be classified as Self-compacting Concrete if the requirements for all

three characteristics are fulfilled.

3.2 Workability and Acceptance criterion So far, no single test method has been developed to characterize SCC properties. The following

table enlists the test methods for determining various fresh parameters of SCC, which are

established by EFNARC.



Table 3.1: List of test methods for workability properties of SCC

Sr. no Method Property

1 Slump-flow by Abrams cone Filling Ability

2 T50 Slump-flow Filling Ability

3 J-Ring Passing Ability

4 V-funnel Filling Ability

5 V-funnel at 5 Minutes Segregation Resistance

6 L-Box Passing Ability

7 U-Box Passing Ability

8 GTM-Screen Test Segregation Resistance

Workability Criteria:

These requirements are to be fulfilled at the time of placing. Typical acceptance criteria for Self-

compacting Concrete with a maximum aggregate size up to 20 mm

are shown in Table 7.

Table 3.2: Acceptance Criteria for Self Compacting Concrete

Sr.

No Method Unit

Typical range of Values

Minimum Maximum

1 Slump flow by Abrams Cone mm 650 800

2 T50 Slump Flow sec 2 5

3 J-ring mm 0 10

4 V-funnel sec 6 12

5 V-funnel 5 minutes sec 0 3

6 L-Box (h2/h1) 0.8 1

7 U-Box (h2-h1)mm 0 30

8 GTM Screen Test % 0 15

3.3 Test Methods

3.3.1 Slump flow and T50 The slump flow is used to measure free flow of SCC horizontally in the absence of obstructions.

The diameter formed by the concrete paddy is a measure for the filling ability of the concrete. This is

a simple, rapid test procedure. It does not gives any indication of passing ability between

reinforcement without blocking, but may give some indication of resistance to segregation.

3.3.1.1 Equipment

Mould of any shape of truncated cone with the internal dimensions 200 mm diameter at

the base, 100 mm diameter at the top and a height of 300 mm, confirming to EN 12350-2

Base plate of a stiff non absorbing material, at least 700 mm square, marked with circle

marking the central location for a slump cone, and for the concentric circle of 500 mm

diameter .

Trowel, Scoop, Measuring Tape, Stopwatch.



3.3.1.2 Procedure

Base plate and slump cone is moistened and placed on a level ground with slump cone

placed centrally on the base plate then about 6 litre of concrete is filled with scoop.

Do not tamp, simply strike off the concrete level with the top of the cone with trowel.

Surplus concrete is removed from around the base of the cone and the cone is raised

vertically to allow the concrete flow out freely.

Simultaneously, start the stopwatch and record the time taken for the concrete to reach

500mm spread circle.

Measure the final diameter of the concrete in two perpendicular directions.

Average of the two measured diameter is calculated. Note any border of mortar or cement

paste without coarse aggregate at the edge of the pool of the concrete

3.3.1.3 Interpretation of Result

The higher the slump flow value, the greater its ability to fill formwork under its own weight. A

value of at least 650 mm is required for SSC. The T50 time is a secondary indication of flow. A

lower time indicates greater flowability. The Brite-EuRam research suggested that a time of 3-

7sec is acceptable for civil engineering applications and 2-5secs for housing applications. In case

of severe segregation most coarse aggregate will remain in the center of the pool of concrete and

mortar and cement paste at the concrete periphery. In case of minor segregation a border of

mortar without coarse aggregate can occur at the edge of the pool of concrete.



3.3.2 V-funnel test and V-funnel 5minutes The V-Funnel test is used to determine the filling ability of the concrete with a maximum

aggregate size of 20mm. The funnel is filled with about 12 litre of concrete and the time taken

for it to flow through the apparatus is measured.

After this the funnel can be refilled with concrete and left for 5 min to settle. If the concrete show

segregation then the flow time will increase significantly.

3.3.2.1 Assessment of test

Though the test is designed to measure flowability, the result is affected by the concrete

properties other than flow. The inverted cone shape will cause any liability of the concrete to

block to be reflected in the result. If, for example there is no too much coarse aggregate. High

flow time can be associated with the low deformability due to high paste viscosity, and the high

inter-particle friction.

3.3.2.2 Equipment: V-funnel, Bucket, Trowel, Scoop, Stopwatch.

Img 3.3: Performing V-funnel test

3.3.2.3 Procedure

About 12 litres of concrete is needed to perform the test, sampled normally.

Set the V-funnel on the firm ground.

Moisten the inside surfaces of the funnel.

Keep the trap door open to allow any surplus water to drain.

Close the trap door and place a bucket underneath.



Fill the apparatus completely with concrete without compacting or tamping, simply strike

off the concrete level with top with the trowel.

Open within 10 sec after filling the trap door and allow the concrete to flow out under

gravity.

Start the stopwatch when the trap door is opened, and record the time for the discharge to

complete (the flow time). This is taken to be when light is seen from above through the

funnel. The whole test has to be performed within 5 minutes.

3.3.2.4 Procedure for V-funnel 5Minutes

Do not clean or moisten the inside surfaces of the funnel again.

Close the trap door and refill the V-funnel immediately after measuring the flow time.

Place a bucket underneath.

Fill the apparatus completely with concrete without compacting or tapping, simply strike off the

concrete level with the top with the trowel.

Open the trap door 5 minutes after the second fill of the funnel and allow the concrete to flow out

under gravity. Simultaneously start the stopwatch when the trap door is opened, and record the

time for the discharge to complete (the flow time at T 5 minutes). This is taken to be when light

is seen from above through the funnel.

3.3.2.5 Interpretation of Result

This test measures the ease of flow of the concrete; shorter flow times indicate greater

flowability. For SCC a flow time of 10 seconds is considered appropriate. The inverted cone

shape restricts flow, and prolonged flow times may give some indication of the susceptibility of

the mix to blocking.

After 5 minutes of settling, segregation of concrete will show a less continuous flow with an

increase in flow time.

3.3.3 L-Box Test

This is Japanese based design for under water concrete. It assesses the flow of the concrete and

the extent of blockage by reinforcement. The apparatus consists of a rectangular-section box in

the shape of an ‘L’, with a vertical and horizontal section, separated by a moveable gate, in front

of which vertical lengths of reinforcement bar are fitted.

The vertical section is filled with concrete, and then the gate lifted to let the concrete flow into

the horizontal section. When the flow has stopped, the height of the concrete at the end of the

horizontal section is expressed as a proportion of that remaining in the vertical section (H2/H1in

the diagram). It indicates the slope of the concrete when at rest. This is an indication passing

ability, or the degree to which the passage of concrete through the bars is restricted.

This is a widely used test, it assesses filling and passing ability of SCC, and serious lack of

stability (segregation) can be detected visually.

3.3.3.1 Equipment

L box of a stiff, non-absorbing material, trowel, scoop and stopwatch.

3.3.3.2 Procedure

About 14 litre of concrete is needed to perform the test, sampled normally.



Set the apparatus level on firm ground, ensure that the sliding gate can open freely and

then close it.

Moisten the inside surfaces of the apparatus, remove any surplus water

Fill the vertical section of the apparatus with the concrete sample. Leave it to stand for 1

minute.

Lift the sliding gate and allow the concrete to flow out into the horizontal section.

Simultaneously, start the stopwatch and record the times taken for the concrete to reach

the 200 and 400 mm marks. When the concrete stops flowing, the distances “H1” and

“H2” are measured. Calculate H2/H1, the blocking ratio.

The whole test has to be performed within 5 minutes.

3.3.3.3 Results

If the concrete flows as freely as water, then H2/H1 = 1. Therefore as the test value the

‘blocking ratio’ is nearer to unity, the better is the concrete flowabilty. The EU research

team suggested a minimum acceptable value of 0.8. T20 and T40 times can give some

indication of ease of flow, but no suitable values have been generally agreed.

3.3.4 U-Box Test The test is used to measure the filling ability of self-compacting concrete.

The apparatus consists of a vessel that is divided by a middle wall into two compartments.

An opening with a sliding gate is fitted between the two sections. Reinforcing bars with

nominal diameters of 13 mm are installed at the gate with centre-to-centre spacings of 50

mm. This creates a clear spacing of 35 mm between the bars. The left hand section is filled



with about 20 litre of concrete then the gate lifted and concrete flows upwards into the other

section. The height of the concrete in both sections is measured.

3.3.4.1 Equipment

U box of a stiff non absorbing material, Trowel, Scoop, Stopwatch.

Fig 3.2: U-Box Apparatus

Img 3.5: Filling U-Box



3.3.5 J-Ring Test The test is used to determine the passing ability of the concrete. The equipment consists of a

rectangular section (30mm x 25mm) open steel ring, drilled vertically with holes to accept

threaded sections of reinforcement bar. These sections of bar can be of different diameters and

spaced at different intervals: in accordance with normal reinforcement considerations, 3x the

maximum aggregate size might be appropriate. The diameter of the ring of vertical bars is

300mm, and the height 100 mm.

3.3.5.1 Equipment

Mould, without foot pieces, in the shape of a truncated cone with the internal dimensions 200

mm diameter at the base, 100 mm diameter at the top and a height of 300 mm.

Base plate of a stiff non absorbing material, at least 700mm square, marked with a circle

showing the central location for the slump cone, and a further concentric circle of 500mm

diameter.

Trowel, Scoop, Measuring tape.

JRing a rectangular section (30mm x 25mm) open steel ring, drilled vertically with holes.

In the holes can be screwed threaded sections of reinforcement bar (length 100mm, diameter

10mm, spacing 48 +/- 2mm)

3.3.5.2 Procedure

About 6 litre of concrete is needed to perform the test, sampled normally.

Moisten the base plate and inside of slump cone,

Place base-plate on level stable ground.

Place the JRing centrally on the base-plate and the slump-cone centrally inside it and hold

down firmly.

Fill the cone with the scoop. Do not tamp, simply strike off the concrete level with the

top of the cone with the trowel.

Remove any surplus concrete from around the base of the cone.

Raise the cone vertically and allow the concrete to flow out freely.

Measure the final diameter of the concrete in two perpendicular directions.

Calculate the average of the two measured diameters. (in mm).

Measure the difference in height between the concrete just inside the bars and that just

outside the bars.

Calculate the average of the difference in height at four locations (in mm).

Note any border of mortar or cement paste without coarse aggregate at the edge of the

pool of concrete.

The average height difference calculated should be less than 10mm.



Img 3.6: Performing J-ring Test



CHAPTER 4

4.1 SCC Mix Design The proportioning of SCC is considered complex because it depends on various factors such as

grain size distribution, quantity and quality of aggregates, distribution of size of aggregates,

dosage and quality of super plasticizers and cement content. A highly flowable SCC should have

a good flowability but an adequate resistance to segregation and bleeding until the onset of

hardening.

4.2 Selection of Mix Proportions In designing the SCC mix, it is most useful to consider the relative proportions of the key

components by volume rather than by mass. The following key proportions for the mixes are

listed below:

1. Air content (by volume)

2. Coarse aggregate content (by volume)

3. Paste content (by volume)

4. Binder (cementitious) content (by weight)

5. Replacement of mineral admixture by percentage binder weight

6. Water/ binder ratio (by weight)

7. Volume of fine aggregate/ volume of mortar

8. SP dosage by percentage cementitious (binder) weight

9. VMA dosage by percentage cementitious (binder) weight

Fig 4.1: Items to consider for proportioning Paste fraction/Fluid Phase

4.3 Mix Proportions and Trials The SCC mix design was formulated first on basic strength requirements of normal

strength (25-30MPa). This was followed by aggregate content calculation by volume, cement

Paste

Paste Volume

Paste Rheology

Paste Composition

Powder Content

Powder Composition

Cement SCMs

Aggregate Fines

Other Powders

Admixtures

VMA HRWR

Air Content Water

Content



replacement by volume and finally SP and VMA dosages were formulated based on the

observations from the trial mixes.

While also parallely performing trial batches for medium strength SCC, a total of 9 trial

mixes were casted before finalizing the mix proportions for normal strength SCC.

Beginning with trial 1, the trials were observed for the fresh state properties such as

flowability, passing ability and segregation.

Based on the visual observations (concrete texture during mixing, degree of segregation

during slump flow, flowability during V-funnel and overall bleeding signs) changes were made

in the mix design to eliminate these unwanted characteristics.

4.3.1 The V-funnel Complication In many trials it was observed that even with satisfactory segregation resistance and slump

flow, the V-funnel time was taking too long. Also, if at all the V-funnel time was in range, then

the V-funnel 5min time was taking exceptionally long. It took a sufficiently long time for the

first lump of concrete to fall on opening the trap door, followed by the rest of the concrete mix.

The problem suspected was a kind of arching formed by the coarse aggregate near the notch of

the v-funnel. The coarse aggregate quickly settled to the bottom forming a clog.

4.3.2 The V-funnel solution In order to prevent the coarse aggregate from quickly settling to the base of the V-funnel, it was

necessary to keep the particles in suspension for the duration of the test being performed. Hence,

the use of the viscosity modifying admixture was proposed.

Trial mixes, after administering VMA dosages showed highly improved segregation and bleed

resistance. Moreover, the V-funnel and V-funnel 5mins parameters were also well under control.

Fig 4.2: Aggregate Blocking and Flowing Through Restricted Spaces



Img 4.1: slump flow with 0% VMA

Img 4.2: Slump Flow 0.2% VMA



Img 4.3: Slump Flow with 0.3% VMA



CHAPTER 5

5.1 Hardened Characteristics This chapter shall illustrate the test results for the basic hardened strength characteristics

of Self Compacting Concrete. The mix design is the one pertaining to trial 9 of Table 4.1.

The tests carried out were:

a) 7-Days cube compressive strength (IS 516 : 1959)

b) 14-Days cube compressive strength (IS 516 : 1959)

c) 14-Days Split tensile Strength (IS 5816 :1999)

d) 14-Days Flexural Strength (IS 516 : 1959)

e) 14-Days Stress-Strain Relationship

Note: Hardened tests are to be usually performed at 28-days but tests for 14-days were carried

out due to shortage of time of the training.

The samples were kept completely immersed in water for the curing period in curing tanks

outside the casting laboratory. Specimens were surface dried after removing them from water

before testing for strength parameters.

Test Specimens:

1. Cubes of dimension 150mm*150mm*150mm (6 nos)

2. Cylinders of dimension 150mm dia, 300mm height (6nos)

3. Prisms 100mm*100mm*500mm (3nos)

5.2 Normal Strength Mix

Cement Water Coarse

Agg Fine Agg

Fly Ash SP VMA W/C ratio

W/P

254.1 183 725.3 930.8 211.3 2.29% 0.3% 0.7202 1.0381

5.3 7-Days Cube Compressive strength

Table 5.1: 7-day Cube Compressive Strength Data

Cube Date of casting Date of Testing Failure

load (kN)

Compressive strength (Mpa)

Average Compressive

Strength (Mpa)

1 22/06/2015 29/06/2015 390 17.33

19.4 2 22/06/2015 29/06/2015 480 21.33

3 22/06/2015 29/06/2015 440 19.56



Result: The 7-Days Cube Compressive Strength was 19.4MPa

Img 5.1: Performing Cube Compression Test

5.4 14-Days Cube Compressive Strength

Table 5.2: 14-days Cube Compressive Strength

Cube Date of casting Date of Testing Failure

load (kN)

Compressive strength (Mpa)

Average Compressive

Strength (Mpa)

1 22/06/2015 7/07/2015 640 28.44

26.66 2 22/06/2015 7/07/2015 600 26.67

3 22/06/2015 7/07/2015 560 24.88

Result: The 14-Days Cube Compressive Strength was 26.66MPa



5.5 14-Days Split Tensile Strength

The test was performed in accordance with IS 5816: 1999.

The Split Tensile Strength is calculated according to the formula:

2P

STSld

Where,

STS = Split tensile Strength (MPa)

P = Failure Load (N)

l = Length of specimen (mm)

d = Diameter of Specimen (mm)

Test Data: Weight of specimen holder = 93.09N

Weight of cover plate = 127.53N

Total Additional load (A) = 0.22kN

Table 5.3: 14-days Split Tensile Strength Data

Specimen Weight

(kg)

Failure Load

(kN)

Total

Failure

Load (kN)

STS

(MPa)

Average

STS

(Mpa)

1 13.0 157.8 158.02 2.235

2.036 2 12.52 130.0 130.22 1.842

3 12.34 143.3 143.52 2.030

Result: The Average Split Tensile Strength of the SCC mix at 14 – Days is

2.036Mpa



Img 5.2: Cylindrical Specimens after STS test

Img 5.3: Test setup for STS test



5.6 14-Days Flexural Strength (Modulus of Rupture) The test was performed using four-point load setup. The central two points were spaced at

0.133m and 0.05m overhang beyond each side supports.

The flexural strength was calculated using basic moment equations as given below;

cr

Mf

Z

………………………………...(1)

( 0.1)

2 3

P lM X

……………………………..(2)

2

6

bdZ

………………………………Section Modulus for rectangular section

M = Bending Moment at Critical section

Z = Section Modulus of test Specimen

P = Failure Load (N)

l = Length of Specimen (m)

b = Width of Specimen at Critical Section (m)

d = Depth of Specimen at Critical Section (m)

For the tested specimens,

l = 0.5m

b = 0.1m

d = 0.1m

Table 5.4: 14-days Flexural Strength Test Data

Specimen Failure Load (kN) Flexural Strength crf

(MPs)

Average Flexural

Stength (MPa)

1. 13 5.2

4.7 2. 11 4.4

3. 11.3 4.52

Result : The average 14-days modulus of rupture for the SCC mix was 4.7MPa

Interpretation: The above value for flexural strength is found out to be very high in comparison

with ordinary concrete for normal strength. This result is suspected to be an outcome of improper

testing equipment.



Img 5.4: Test Setup for Flexural Strength Test

5.7 14-Days Stress-Strain Analysis

The Stress-Strain Analysis was carried out on cylindrical specimens of 150mm diameter and

300mm height. The loading machine used was a universal testing machine manufactured by

CONTROLS. The test was performed at a displacement control rate of 3.35µm/s until failure.

There was a single LVDT placed in order to measure the uniform displacement of the specimen.

Specimen Peak Load (kN) Strain at Peak Load (mm/mm)

1. 385.3 0.00417

2. 323.3 0.0037

3. 315 0.0035 Table 5.5: Critical Points data for Stress-strain analysis

5.7.1 Stress V/S Percentage Strain Curves



Fig 5.1: Stress-%Strain Curves for cylindrical specimens

As evident from the stress strain curve shown in Fig: 4, the data for specimen 3 shall be

discarded. The sudden fall in was due to uneven surface finish of the specimen. It is noted that

Care must be taken henceforth for surface and specimen preparation before performing

stress analysis.

Result: The average strain for the test was found to be 0.0039 mm/mm at failure.

The modulus of Elasticity was determined as the tangent modulus of the straight line

portion in the stress-strain curve. The Average of the tangent modulus of elasticity of specimen 1

and specimen 2 was computed as 20880.78MPa

0

5

10

15

20

25

0 0.2 0.4 0.6 0.8 1 1.2

Stre

ss (

MP

a)

%Strain

Stress V/S Percentage Strain

Specimen 1

Specimen 2

Specimen 3



Img 5.5: Test Setup for Stress Analysis

5.8 Hardened Properties Discussion

The tests carried out at 7-days and 14-days revealed that the concrete had compressive and

tensile strengths in an acceptable range. The flexural strength was computed to be on the higher

side of expected value, reason being suspected as faulty/improperly calibrated test equipment.

Also, Modulus of elasticity for the SCC mixture was found to be 20880.78MPa

It is learnt from this experience that preparation of specimen and following test protocols to the

very detail, as per established standards should be given utmost importance. This is crucial to

yield accurate and reliable test results and economize the study.



CHAPTER 6

6.1 Concrete Rheology SCC mixtures are much more fluid than conventional concrete mixtures. Rheology is the

science dealing with the flow of materials. SCC is a concrete whose very foundation was built on

rheological characteristics. With SCC, the flowing properties of a concrete mixture are

paramount and rheology helps us understand and differentiate performance in a fundamental

way.

6.2 The Bingham model It is quite prominent that concrete should be rheologically described according to the Bingham

Model. The model proposes two constants defining the flow of a material: the yield stress, which

is defined as the amount of force required to initiate flow of material, and the plastic viscosity,

defined as the material’s internal resistance to flow. For concrete, these parameters are measured

through the use of a concrete rheometer.

These rheometers are very useful for studying concrete performance. The typical

concreterheometer will measure torque values as a sample of concrete is sheared at different

rates. The Plot in Fig. 5 shows the increased torque on the impellar as the rate at which spins

through concrete increases the rheological data is derived by plotting a best-fit line through the

set of points. The extrapolated point at which this line intersects the y-axis is the yield stress of

the material, which is the point at which the mixture will “yield” or begin to flow. Applied stress

levels above this point will cause the concrete to flow, but below this level the concrete will not

move. The yield stress is inversely proportional to the slump of the concrete.

For SCC, the yield stress should be very low so that the material will flow exclusively under its

own weight and the techniques required for placing and consolidating conventional concrete are

not required.



Fig 6.1: Bingham Model (Image Courtesy: ICAR Rheometer, GERMANN INSTRUMENTS)

The viscosity of SCC mixtures can vary significantly depending on materials, mixture

proportions and admixtures. This is important as it can impact certain performance attributes

such as segregation resistance. Theologically then, SCC mixtures are characterized as having low

yield stress and a plastic viscosity that varies with the intended applications.

Apart from using the Concrete Rheometer, the V-funnel time and T50 test aslo provide a

relative and reliable indication of plastic viscosity.



Img 6.1: ICAR Concrete Rheometer



CONCLUSION

The report presented here is a comprehensive compilation of the work carried out at IIT

Roorkee during a course of two months. It includes all experimental data and results pertaining

to the study of normal strength self-compacting concrete derived in the mentioned period.

It is concluded from this report that establishing the right constituent proportions of an SCC

mixture is highly dependent on required performance criteria. It is very important that a mix

satisfies all required test parameters in its fresh state in order to be called SCC. However, it is

also concluded that attaining a robust design for a given SCC requirement is a challenge and

further study needs to be carried in this regard.

With respect to hardened properties, the SCC mixture provides quite satisfactory strength

results at compared to conventional slump concrete. For a well-designed and sufficiently flowing

SCC mixture, the surface finishes are decent and may fulfill aesthetic standard requirements.

Finally, SCC being a non-Newtonian fluid, further study is necessary to better understand its

flow characteristics so as to optimize fluidity, keeping adequate mix stability.



REFERENCES

1. Daczko, Joseph A. (2012), Self-Consolidating Concrete Applying What We Know, CRC

Press.

2. Kumar, Rajesh (2014), SRENGTH AND DEFORMATION CHARACTERISTICS OF

OVERLY REINFORCED SELF COMPACTING CONCRETE BEAMS, Doctoral

Thesis, Department of Civil Engineering, Indian Institute of Technology Roorkee,

Roorkee 247667, Uttarakhand, India.

3. Saurabh, Anuj (2015), A Review of The Properties of Recycled Aggregate Concrete,

M.Tech Thesis, Department of Civil Engineering, Indian Institute of Technology

Roorkee, Roorkee 247667, Uttarakhand, India.

4. IS 10262 (2009). Indian Standard Concrete Mix Proportioning – Guidelines. (First

Revision). Bureau of Indian Standards, New Delhi.

5. IS 2386 (1963). Indian Standard Method of Test for Aggregates for Concrete. Part I-

Particle Size and Shape. Bureau of Indian Standards, New Delhi.

6. IS 516 (1959-Reaffirmed 1999). Indian Standard Methods of Tests for Strength of

Concrete. Bureau of Indian Standards, New Delhi.

7. IS 5816 (1999-Reaffirmed 2004). Indian Standard Splitting Tensile Strength of Concrete

-Method of Test. (First Revision). Bureau of Indian Standards, New Delhi.

8. ACI 237R-07, Emerging Technology Series, Self-Consolidating Concrete, American

Concrete Institute.

9. Murthy, Krishna N., Rao, Narsimha A.V., Reddy, Ramnan I. Vand, Reddy, Vijaya

Sekhar M., (2012) Mix design Procedure for Self Consolidating Concrete, IOSR Journal

of Engineerinh (IOSRJEN), Volume 2, Issue 9, pp 33-41.

10. Specifications and Guidelines Self-Compacting Concrete (2002), EFNARC, Association

House, 99 West Street, Farnham, Surrey GU9 &EN, UK.

11. Kulasegaram, S., Krihaloo, B.L., Ghanbari, A., (2010) Modeling the flow of self-

compacting concrete, INTERNATIONA JOURNAL FOR NUMERICAL AND

ANALYTICAL METHODS IN GEOMECHANICS, Wiley Online Library DOI:

10.1002/nag.924.

12. Okamura, H., and Ozawa, K., (1994), Self Compactible High Performance Concrete in

Japan, ACI International Workshop on High Performance Concrete, SP-159, P. Zia, ed.,

American Concrete Institute, Farmington Hills, Mich., pp. 31-44.

13. Ouchi, M., (2001), Current Condition of self-Consolidating Concrete in Japan,

Proceedings of the Second International Symposium on SCC, K. Ozawa and M. ouchi,

eds., Tokya, pp.63-68.



APPENDIX

1. Application to program and Consent Letter From Parent Institute, Veermata

Jijabai Technological Institute, Mumbai.



2. Approval letter from Indian Institute of Technology Roorkee.

summer research report

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