Rubberized Cocrete

Civil Engineering Department SATI 2012

1 | P a g e

ABSTRACT

In recent years, there has been a considerable interest in resolving one of the important

environmental problems like the solid waste management. Out of the variety of common

solid waste, the disposed waste tyre parts, abundantly found in the landfill, has been found

as a non-biodegradable type. However, it is known that the reinforced rubber material

shows the hysteresis behaviour under cyclic loading and offers a possibility for its re-usage

as a filler material whenever high damping is required. In this report an effort has been

made to study experimentally the feasibility of using the waste tyre parts as coarse

aggregate in cement concrete. The present investigation has been started with the

consideration of M20 grade vibrated concrete as control mix or reference mix. A test

program has been carried out to identify the necessary information about the mechanical

properties of rubberized concretes. Tyre rubber chips have been used as coarse aggregate

in the production of Rubberized concrete mixtures by partially replacing the coarse

aggregate with rubber. In order to keep the brevity, five designated rubber contents varying

from 3%, 6%, 9%, 12% and 15% by total aggregate volume have been used in the present

investigation. Experiments have been conducted for compressive test, split tensile strength

test, flexural strength test, determination of the Young’s modulus, determination of Dynamic

modulus of elasticity, Static ultrasonic pulse velocity test, the Dynamic ultrasonic test and

Rebound hammer test etc. in accordance with the IS standards. Using this grade of


2 | P a g e

concrete a set of 250×250×100 mm size tiles have been prepared as a possible example of

the application part.

It has been observed from the results that the concrete containing rubber aggregate has

improved workability, requiring less amount of water for same mix design and a reduction in

mechanical properties (Compressive strength)


3 | P a g e

CONTENTS

TITLE

CHAPTER 1 INTRODUCTION 1.1 General 1.2 Objectives of the Project

CHAPTER 2 LITERATURE REVIEW 2.1 Introduction 2.2 Review of relevant research 2.3 Scope of the Project Work CHAPTER 3 CHARACTERISTICS OF MATERIAL 3.1 Introduction 3.2 Cement 3.3 Scrap Tyre Rubber

3.4 Aggregate CHAPTER 4 EXPERIMENTAL INVESTIGATIONS 4.1 Introduction 4.2 Material Testing 4.3 Mixing and Casting of samples 4.4 Experimental Setup CHATER 5 RESULTS AND DISCUSSION 5.1 Fresh Concrete Properties

(a) Workability (b) Compressive Strength 5.2 Hardened Concrete Properties

PAGE NO. 7 7 8 9 9 9

16

17 17 17 17 20 23

24 24 27 27 27

31

31


4 | P a g e

(a) Compressive Test (b) Strain 5.3 Closing Remarks 5.4 Discussion CHAPTER 6 CONCLUSION AND FUTURE SCOPE

6.1 Conclusions

6.2 Future Scope REFERENCES

34 35

36

37 38


5 | P a g e

LIST OF TABLES Table No. Page No.

Table 3.2.1: Physical Properties of Portland Pozzolana Cement ……… 18

Table 3.2.2: Chemical Composition of Portland Pozzolana Cement (%) 19

Table 3.3.1: Typical constituent materials of tyre………………………. 21

Table 3.4.1: Physical properties of materials…………………………… 23

Table 4.3.1: Mix considered for Rubberized concrete…………………. 25

Table 4.3.2: Test Samples Details……………………………………….. 27

Table 5.2.1: 28 days Strength of Cube (IN Mpa).................................. 32

Table 5.2.2: 28 days Strength of cylinder (IN Mpa).............................. 33

Table 5.3.3: Strain Comparison : for cylindrical specimens ............... 33


6 | P a g e

List of Figure Table No. Page No.

Figure 3.3.1: Chipped rubber samples……………………………... 22

Figure 4.3.3: Casting of Concrete Block…………………………… 26

Figure 4.5.1: Compressive test of a cement Cube using UTM...... 28

Figure 4.5.2: Compressive test of a concrete Cube using UTM… 29

Figure 4.5.3: Compressive test of a Cylinder using UTM………… 30


7 | P a g e

CHAPTER 1 INTRODUCTION

1.1 General

Solid waste management has gained a lot of attention to the research community in recent

days. Out of the various solid waste, accumulated waste tyres, has become a problem of

interest because of its non-biodegradable nature [Malladi, 2004]. Most of the waste tyre

rubbers are used as a fuel in many of the industries such as the thermal power plant,

cement kilns and brick kilns etc. Unfortunately, this kind of usage is not environment friendly

and requires high cost. Thus, the use of scrap tyre rubber in the preparation of concrete has

been thought as an alternative disposal of such waste to protect the environment. It has

been observed that the rubberized concrete may be used in places where desired

deformability or toughness is more important than strength like the road foundations and

bridge barriers. Apart from these the rubberized concrete having the reversible elasticity

properties may also be used as a material with tailorable damping properties to reduce or to

minimize the structural vibration under impact effects [Siddique et al. (2004)].

The difficulties associated to the theoretical investigations to identify the mechanical

properties of the rubberized concrete have necessitated the need for the experimental

investigations on rubberized concrete. Therefore, in this study an attempt has been made to

identify the various properties necessary for the design of concrete mix with the coarse tyre

chips as aggregate in a systematic manner. Properties of rubberized concretes, in the

present experimental investigation, the M20 grade concrete has been chosen as the


8 | P a g e

reference concrete specimen. Coarse tyre rubber chips, has been used as coarse

aggregate with the replacement of conventional coarse aggregate.

1.2 Objectives of the Project

To investigate the mechanical properties associated to the rubberized concrete (using the

Portland slag cement), the following items have been kept as the objective.

1. Study the feasibility of incorporating coarse tyre rubber chips as coarse aggregate in

concrete mixes and determine the change in the properties after the incorporation of the

rubber into the concrete mix.

2. Experimental verification of the published results on rubberized concrete, various

relevant standards, various properties of rubberized concrete, and their relationship to

plain concrete.

3. Investigation on the influence of the rubber content on the mechanical properties of

rubberized concrete starting with the 0% rubber content (i.e., without rubber) and up to

15% rubber content in the M20 grade concrete (i.e., with a partial replacement of the

coarse aggregate by 3%, 6%, 9%, 12%, and 15% by volume of the total coarse

aggregate material). For convenience, the mix design for M20 grade concrete has been

done according to IS: 10262(1982).

4. Measurement/determination of the mechanical properties (Compressive Strength,

Tensile Strength, Flexural Strength, and Young’s Modulus) of all concretes.

5. Conduct the non-destructive tests like Rebound hammer test of the rubberized concrete

and conventional specimens.


9 | P a g e

CHAPTER 2 LITERATURE REVIEW

2.1 Introduction

There are numerous research reports available on the mechanical and chemical properties

of cement concrete. However, the research works carried out for the rubberized cement

concrete are found to be limited. The available results indicate that the influence of the size,

proportion, and surface texture of rubber particle on the strength of concrete contaminating

tyre rubber is significant. For the sake of brevity, only the relevant works concerning the

influence of rubber on the mechanical behaviour of the rubberized concrete have been cited

in the chapter.

2.2 Review of relevant research

Zheng et al. (2008) worked on rubberized concrete and they replaced the coarse aggregate

in normal concrete with ground and crushed scrap tyre in various volume ratios. Ground

rubber powder and the crushed tyre chips particles range in size from about 15 to 4 mm

were used. The effect of rubber type and rubber content on strength, modulus of elasticity

were tested and studied. The stress-strain hysteresis loops were obtained by loading,

unloading and reloading of specimens. Brittleness index values were calculated by

hysteresis loops. Studies showed that compressive strength and modulus of elasticity of

crushed rubberized concrete were lower than the ground rubberized concrete.


10 | P a g e

The reduction in strength explains below:

(a) The replacement of coarse aggregate by softer rubber particle resulted in quantity

reduction of strong load carrying material.

(b) The weak bond between the rubber particles and cement paste.

(c) Stress concentration was more at the boundaries of rubber aggregate.

While increasing the percentage of rubber contents the compressive strength, static

modulus of elasticity and dynamic modulus of elasticity of the rubberized concrete

decreases. When ground rubber used in concrete the value of compressive strength and

the modulus of elasticity will be more compare to crushed rubber chips. The rubberized

concrete had a higher ductility performance than the normal concrete.

Taha et al. (2008) used chipped tyre rubber and crumb tyre rubber to replace the coarse

and fine aggregate respectively in the concrete at the replacement levels of 25%, 50%, 75%

and 100% by volume. The tyre rubber was chipped in two groups of size 5 to 10 mm and 10

to 20 mm. The crumb tyre rubber of size 1 to 5 mm was used. These were mixed with a

ratio of 1:1.

The results showed that

(a) Workability increase with the increase in rubber content in the concrete.

(b) The strength of concrete showed better result when using crumb tyre rubber in concrete.


11 | P a g e

The compressive strength of concrete was reduced with the increasing of rubber

percentage. The three main reasons responsible for reduction in strength are:

(1) The deformability of rubber particles compared with the surrounding cement paste,

which results in initiating cracks around the rubber particles.

(2) Due to the weak bond between rubber particles and cement paste.

(3) Due to the possible reduction of the concrete matrix density which depends on the

density, size, and hardness of the aggregate.

In this paper the authors concluded that the larger the size of the tyre rubber particles,

lower the compressive strength of rubberized concrete. hardened properties of concrete

using different types of tyre rubber particle as a replacement of aggregate in concrete. The

different types of rubber particles used were tyre chips, crumb rubber and combination of

tyre chips and crumb rubber. These particles were used to replace 12.5%, 25%, 37.5% and

50% of the total mineral aggregate by volume. The results showed that the fresh rubberized

concrete had lower unit weight and workability compared to plain concrete. Result showed

large reduction in strength and modulus of elasticity in concrete when combination of tyre

rubber chips and crumb rubber were used as compared to that when these were used

individually. It was found that the brittle behavior of concrete was decreased with increased

rubber content. The maximum toughness index indicated the post failure strength of

concrete occurred with 25% rubber content. Ganjian et al. (2008) investigated the

performance of concrete mixture incorporating 5%, 7.5%, and 10% tyre rubber by weight as

a replacement of aggregate and cement. Two set of concrete mix were made. In the first set


12 | P a g e

chipped rubber replaced the coarse aggregate and in the second set scrap tyre powder

replaced cement. The durability and mechanical test were performed. The result showed

that up to 5% replacement in both sets no major changes occurred in concrete

characteristic. The reasons for reduction in the compressive strength of concrete when

rubber was used: (1) The concrete containing rubber particles is much softer than hardened

concrete without rubber. The cracks would rapidly develop around the rubber particles

during loading. (2) Due to lack of proper bonding between rubber particles and the cement

paste. The continuous and integrated matrix is not available against load; hence the applied

stresses are not uniformly distributed in the concrete matrix. (3) The compressive strength

of concrete will be depending on physical and mechanical properties of materials, but the

part of the aggregate was replaced by rubber particles so that the volume of aggregate was

reduced. ompared to traditional aggregates. The presence of rubber particles in concrete

reduced mass stiffness and also reduced its load bearing capacity. As the lower specific

gravity of rubber and lack of bonding, the rubber particles tend to move toward the top

surface of the mould during casting and vibrating test specimens, so that the concentration

of rubber particles is more at the top layer of specimens.

Bakri et al. (2007) replaced the coarse aggregate by waste tyre rubber to produce early age

concrete. Two different concrete mix viz. Rubberized concrete and rubber filler in concrete

were used. In rubberized concrete they replaced the coarse aggregate with the rubber. It

was suggested that the compressive strength and density of concrete depend on the


13 | P a g e

amount of rubber added in the concrete. In the rubberized concrete containing little amount

of added rubber, the density and compressive strength were reduced to nearly 80%, as

compared to ordinary concrete. Huang et al. (2004) prepared a rubberized Portland cement

concrete with a portion of aggregate replaced by tyre rubber particles. Preliminary

experiment was conducted to determine the mechanical properties of concrete. A

parametric analysis was conducted using finite element analysis. It was found that

rubberized concrete had very high toughness. However its strength decreased when the

rubber content increased. The rubberized concrete was treated as a multiphase particulate

filled composite material.

It was found that the strength of rubberized concrete could be increased by reducing the

rubber chip size, using stiffer coarse aggregate, employing uniform coarse aggregate size

distribution and using a hard cement mortar if it is a high strength or using softer cement

mortar if it is good at ductility. adi (2004) had performed the experimental investigation on

the rubberized cement concrete and had carried out the mechanical properties of fresh and

hardened concrete. He replaced the fine aggregate by rubber fiber and rubber crumb.

Three main group of tests were carried out, in the first group fine aggregate was replaced

by rubber fiber in proportions of 5%, 10%, 15%, 20%, in the second group fine aggregate

was replaced by rubber crumb in proportions of 1%, 10%, 20%, 30% and in the third group

fine aggregate was replaced by rubber crumb and rubber fiber treated with 0.1 NaOH in the

proportions of 10% for both by weight of fine aggregate. It was found that the workability,

density and water absorptions decreased with the increase in rubber content. Strength of


14 | P a g e

concrete for rubber fiber was reduced by 37% with replacement of 20% of fine aggregate. In

the case of rubber crumb, the loss of strength was 37% with 30% replacement of fine

aggregate. It was shown that the strength of concrete was decreased when rubber content

was increased but the modulus of elasticity was increased with the increase in rubber

content. The rubberized concrete having rubber treated with NaOH increased the

compressive strength up to 18% as compared to that of untreated rubberized concrete.

Li et al. (2004) tried to improve the strength and stiffness of used rubberized concrete by

using large size chipped rubber fibres (approximately 25mm, 50mm and 75mm long and

5mm thick) and rubber treated with NaOH solution. They concluded that such fibre rubbers

give better result compare to chipped rubbers, but the NaOH surface treatment does not

work for larger sized chipped tyres.

Hernandez-Olivares et al. (2002) investigated the dynamic characteristics of rubberized

concrete material. Because of the unique elasticity properties of rubber material, the

rubberized concrete showed potential advantages in reducing or minimizing vibration and

impact effect. He influence of adding two kinds of rubber crumb and chipped. They made

three groups of concrete mixtures,

In group A: crumb rubber was used to replace fine aggregate, in group B: chipped rubber

was used to replace coarse aggregate and in group C both types of rubber were used in


15 | P a g e

equal volumes. All the three groups had eight different rubber contents in the range of 5–

100%. It was found that the there was a decrease in slump with increase in rubber content

and mixtures made with fine crumb rubber were more workable than those with coarse tyre

chips or a combination of tyre chips and crumb rubber. They reported that when the rubber

content was increased, rubberized concrete specimens tend to fail gradually and failure

mode shape of the test specimen was either a conical or columnar. The decrease in

compressive strength of concrete with the addition of coarse rubber-chips was more as

compared to the decrease in the strength with the addition of fine crumb rubber. Because of

low specific gravity of rubber particles, unit weight of mixtures containing rubber decreased

with the increase in the percentage of rubber content. Increase in rubber content increased

the air content, which in turn reduced the unit weight of the mixtures.

Fattuhi and Clark (1996) have suggested that rubberized concrete could possibly be used in

the following areas: Where vibration damping was needed, such as in foundation pad for

rotating machinery and in railway stations. For trench filling and pipe bedding, pile heads,

and paving slabs and where resistance to impact or blast was required such as in railway

buffers, jersey barriers and bunkers.


16 | P a g e

2.3 Scope of the Project Work

The scope of present investigation is the study of recycling of rubber waste generated in the

form of discarded tyres and possibility of using waste tyre rubber as partial replacement of

coarse aggregate in order to produce rubberized concrete. The purpose of this investigation

is to see the effect on properties of concrete with different proportions of coarse tyre rubber

chips. The methodology is to replace different proportions of the coarse aggregate with

coarse rubber chips and test the properties of fresh and hardened concrete. Further Non

destructive tests also will be conducted.


17 | P a g e

CHAPTER 3 CHARACTERISTICS OF MATERIAL

3.1 Introduction

The present chapter concentrates on the characterization of basic material of concrete e.g.

cement, sand, aggregate and chipped Tyre rubber.

3.2 Cement

The cement used in the project is MYCEM’s fly ash based Portland Pozzolana Cement. It

conformed to the requirements of Indian standard specification IS: 1489 (Part-I) 1991. The

results are given in Table-1. The tests on cement were carried out as per IS: 4031(1988).

Vicat Apparatus and Le-Chaterlier flasks are used to find out Consistency and specific

gravity of cement respectively.


18 | P a g e

Table 3.2.1: Physical Properties of Portland

Characteristics Experimental results IS 455 :1989 Requirements

Consistency (%) 37%

Setting Time (Min.)

(i) Initial Setting Time 88 Min. 30 min, (Minimum)

(ii) Final Setting Time 620Min. 600 min, (Maximum)

Comp. Strength (M.Pa)

(i) 3 days 23.4 16 Mpa (Minimum)

(ii) 7 days 28.8 22 Mpa (Minimum)

(iii) 28 days 36.12 33 Mpa (Minimum)


19 | P a g e

Table 3.2.2: Chemical Composition of Portland Pozzolana

Cement (element by %)

(As Per IS: 1489 (Part-I) 1991)

S.

No.

Characteristic Requirement

(% by Mass)

Method of

Test Ref. to IS

Code

1. LOSS on ignition 5.0 4032 : 1985

2. Magnesia ( MgO ) 6.0 4032 : 1985

3. Sulphuric Anhydride(SO3) 3.0 4032 : 1985

4. Total Chloride (Cl) 0.1 4032 : 1985

5. Insoluble material X + 4.09(100-x)/100 4032 : 1985


20 | P a g e

3.3 Scrap Tyre Rubber

The classification of scrap tyre:

Tyre may be divided into two types- car and truck tyres. Car tyres are different from truck

tyres with regard to constituent materials (e.g. natural and synthetic rubber). Usually three

main categories of discarded tyre rubber have been considered such as chipped, crumb

and ground rubber.

(1) Chipped or shredded rubber is used to replace the gravel. To produce this rubber, in the

first stage the rubber has length of 300–430 mm long and width of 100–230 mm wide. In the

second stage its dimension changes to 100–150 mm by cutting. If the shredding is further

continued particles of about 13–76 mm in dimension are produced.

(2) Crumb rubber is used to replace the sand. This rubber is manufactured by special mills

where big rubbers change into smaller particles. In this procedure particles of about 0.425–

4.75 mm in dimension are produced.

(3) Ground rubber is used to replace the cement. In this category particles of about 0.075

0.475 mm in dimension [Ganjian et al. (2008)].

The typical constituent material of tyre is shown in Table-3.3.1.


21 | P a g e

Table 3.3.1: Typical constituent materials of tyre

[http://www.rma.org/scrap_tires].

Composition weight (%) Car tyre Truck tyre

Natural rubber 14 27

Synthetic rubber 27 14

Black carbon 28 28

Fabric, filler accelerators, and anti zonants 16-17 16-17

Steel 14-15 14-15

In the present study the old rubber from heavy vehicles, such as truck tyre was used. The

chipped rubber samples were obtained by cutting the tyre manually. The tyre chips 20 mm

sieve passing were used in this study.. Tyre particles were not pre-treated before their

incorporation into the concrete mixture. The chipped tyre rubber used in this investigation is

shown in Figure-3.3.1.


22 | P a g e

Figure: 3.3.1

Chipped rubber samples


23 | P a g e

3.4 Aggregate

Natural river sand with a maximum size of 4.75 mm was used as fine aggregate. Crushed

stone with a maximum size of 20 mm was used as coarse aggregate. It was tested as per

Indian Standard specification IS: 383(1970). The physical properties of aggregate were

tested according IS: 2386(1963). The physical properties of fine and coarse aggregate are

presented in Table-3.4.1. The particle gradation curves of fine and coarse aggregate are

shown in Figure-3.4.1 conforming to zone II as per IS: 383(1970).

Table 3.4.1: Physical properties of materials

Property Material

Fine Aggregate Coarse Aggregate

Bulk density (kg/m3) 1731 1547

Specific gravity 2.5 2.88

Fineness modulus 3.17 5.6

Water absorption (%) 3.4% 1.4%


24 | P a g e

Result and Discussion

Testing of samples

(7 days and 28 days)

Testing of samples

(7 days and 28 days)

Curing of Samples

Material Characteristics

(Physical and ChemicalProperties)

CHAPTER 4

EXPERIMENTAL INVESTIGATIONS 4.1 Introduction The present chapter focuses to study the effect of partial replacement of coarse aggregate by coarse tyre rubber chips on the fresh concrete property (e.g. slump test) and hardened concrete properties e.g. compressive strength, split tensile strength, modulus of elasticity, flexural strength, dynamic ultrasonic pulse velocity and NDT test (rebound hammer and

static ultrasonic pulse velocity). Experimental investigation was carried out in five stages as shown in Figure-4.1.1.

First stage Second stage Third stage Fourth stage Fifth stage

Figure-4.1.1


25 | P a g e

4.2 Material Testing The material properties for all ingredient of concrete are given in Chapter 3. 4.3 Mixing and Casting of samples 4.3.1 Mix proportion There were six type of mix considered; of which One control mixture MC-00 (without rubber) was designed as per Indian Standard Specification IS: 10262(1999) (1: 1.34: 2.49, W/C

ratio = 0.42) to achieve 28 days strength 25 MPa. The other five concrete mixes were made by replacing the coarse aggregate with 1%, 2%, 3%, 4% and 5% of discarded tyre rubber by weight. The details mixture proportions are given in Table 4.3.1.

Mix Identity Mix Proportions

MC -00 M20 concrete with 100% coarse aggregate

MCR-01 M20 concrete with 99% coarse aggregate + 1% tyre rubber





4.3.2 Procedure

• The control mix was M25 designed as per the design mix in the IS: 10262(1982).

• For all other mixes the proportions of cement, sand and water remained constant

with various proportions of coarse aggregate was replaced by coarse rubber chips.

• All replacement was carried out by volume.

• Normal tap water was used for casting and curing.

• Workability of fresh concrete was measured by slump test immediately after mixing.


26 | P a g e

• The test specimen was cast in steel moulds and dimension of specimen is as per the

standard specimen. All specimens are compacted by using needle vibrator.

• All specimens were removed from moulds after 24 hours.

• All measurement was made by weight and mechanical mixing of the concrete is done.

• The testing of specimens was carried after specimens were surface dry.

• Tests carried out for compressive strength, flexural strength, Split tensile strength,

modulus of elasticity, soundness of concrete with help of ultrasonic pulse velocity,

workability.

• For each test three specimens was used.

Figure:4.3.3


27 | P a g e

4.3 Test Sample Details

The information about the tests, size of specimens, and number of specimens used in this

investigation is shown in Table-8. The picture of casting of specimens is shown in

Figures-4.3.2, and 4.3.3.

Table 4.3.2: Test Samples Details

Tests Sample size No.

7 days Compressive strength 150 × 150 × 150 mm (Cube) 3

28 days Compressive strength & NDT 150 × 150 × 150 mm (Cube) 3

28 days Compressive strength 300 × 150 mm (Cylinder) 3

4.4 Experimental Setup:

Compressive strength test on cubes and cylinder were carried out using the universal

testing machine. Compressive test were carried out on cubes of dimensions 150×150×150

mm after 7 days and 28 days and on Cylinder of dimensions 300 mm length and 150 mm

diameter after 28 days only. For each test and for each mix three specimens were tested.

The compressive strength was computed using the expression ẛc = P/A for cubes and Fc =

P/πr2 where Fc is the compressive stress in MPa, P is the maximum applied load in

Newton and r is the radius of the cylinder in mm. The compressive strength test setup for

cubes and cylinders is shown in Figures: 4.5.1, and 4.5.2.


28 | P a g e

Figure 4.5.1

Figure: Specimens after testing


29 | P a g e

Figure 4.5.2


30 | P a g e

Figure:4.5.3


31 | P a g e

CHATER 5 RESULTS AND DISCUSSION

5.1 Fresh Concrete Properties

(a) Workability

The replacement of coarse aggregate by waste tyre rubber was effect on the workability of

concrete. The workability of rubberized concrete showed a increase with increases of waste

tyre rubber content of total aggregate weight.

Concrete Mix Slum Value (in mm)

MC00 45

MCR01 47

MCR02 56

MCR03 53

MCR04 67

MCR05 71

5.2 Hardened Concrete Properties

(a) Compressive Test

The compressive tests were carried out after 7 days and 28 days for cube and after 28 days

for cylinders. Compression test specimens, 150 mm cubes and 150/300 mm cylinders were

casted according to IS: 516(1959). These specimens were cast in steel forms and wet

cured. Compression test according to IS: 516(1959) was carried out on cubes and cylinder.


32 | P a g e

The specimens were loaded at a constant strain rate until failure. The compressive strength

is decreased with an increase in the percentage of the tyre rubber chips. It can be seen that

the compressive strength of cubes at 28 days curing for control mixture (MC-00) achieved

33.71 MPa. Mixes MCR-1, MCR-2, MCR-3 shows a increase of 7.4%, 1.14% and 0.03%

while MCR-4 and MCR-5 showed reduction of 15.96% and 40.30% respectively, in

comparison with the control mix (MC-00), but mix MCR-3 gives better result than the control

mix. The ratio of cylinder compressive strength and cube compressive strength for normal

concrete (MC-00) is 0.72, which is close to the commonly accepted cylinder/cube

compressive strength ratio for normal concrete. For rubberized concrete at rubber content

of 1%, 2%, 3%, 4%, and 5%, the ratio became 0.72, 0.71, 0.64, 0.58, and 0.66 respectively.

Table Representation of Strength Comparison :

Table 5.2.1

28 days Strength of Cube (IN Mpa)

MC00 33.71

MCR01 36.44

MCR02 34.10

MCR03 33.80

MCR04 28.33

MCR05 19.91


33 | P a g e

Table 5.2.2

28 days Strength of Cylinder (Mpa)

MC00 24.32

MCR01 26.30

MCR02 24.40

MCR03 22.00

MCR04 16.44

MCR05 13.33

(b) Strain Comparison : for cylindrical specimens

Table 5.3.3

MC 00 0.10

MCR01 0.15

MCR02 0.16

MCR03 0.18

MCR04 0.24

MCR05 0.27


34 | P a g e

5.2 Closing Remarks

The following observations were made based on the present study for the replacement of

Chipped tyre rubber in place of coarse aggregate.

• Workability is increased as the percentage of replacement of chipped tyre rubber

increased.

• The compressive strength is increasing up to replacement of 3% rubber and then it is

decreasing on the further replacement of rubber.


35 | P a g e

5.3 Discussion

The reasons for reduction in the strength of concrete when rubber was used.

These factors include:

• Due to a lack of proper bonding between rubber particles and the cement paste as

compared to cement paste and aggregates,

• Due to replacement of the aggregates by rubber particles, the volumes was reduces. On

the other hand, compressive strength of concrete depends on physical and mechanical

properties of the materials.

• During casting and vibrating of test specimens, the rubber particles tend to move toward

the top surface of the mould. The high concentration of rubber particles at the top layer of

the specimens. This is because of the lower specific gravity of the rubber particles.

• Due to non-uniform distribution of rubber particles in the concrete produce no

homogeneous samples and results in reduction in concrete strength.

• The stiffness of rubber is lower as compared to stiffness of coarse aggregate, the

presence of rubber particles in concrete is reduce concrete mass stiffness and also

decreases load bearing capacity of concrete.


36 | P a g e

CHAPTER 6 CONCLUSION AND FUTURE SCOPE

6.1 Conclusions

• The workability generally increased with the increase in rubber content.

• The compressive strength of the rubberized concrete increased up to 3% replacement and

decreased after it.

• Compressive strength of concrete depended on two factors: grain size of the replacing

rubber and percentage added. In general, compressive strength was increased with small

amount of rubber replacement in concrete.


37 | P a g e

6.2 Future Scope

• Determine the effect of rubber on concrete with the replacement of combination of coarse

and fine aggregate.

• Replacement of coarse aggregate with the waste tyre rubber chip having centre

anchorage hole must be studied in various percentages.

• Replacement of coarse and fine aggregate with rubber aggregate in different water-

cement ratio.

• Though the study stopped with the 5% rubber replacing coarse aggregate, higher

replacement percentage may be carried out.

• In the present study the Portland slag cement was used. Further its mechanical properties

can be compared by using ordinary Portland cement.

• Replacement of coarse aggregate with the treated waste tyre rubber chip must be studied.

• The durability experiments may be performed on rubberized concrete.


38 | P a g e

References • IS: 516 (1959). “Indian Standard methods of tests for strength of concrete.” Bureau

of Indian standards, Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi

110002.

• IS: 5816 (1999). “Indian Standard Splitting tensile strength of concrete – methods of

test.” Bureau of Indian standards, Manak Bhavan, 9 Bahadur Shah Zafar Marg, New

Delhi 110002.

• IS: 2386 (1963). “Indian Standard methods of test for aggregates for concrete.”

Bureau of Indian standards, Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi

110002.

• IS: 455 (1989). “Indian Standard Specification for Portland slag cement.” Bureau of

Indian standards, Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002.

• IS: 4031 (1996). “Indian Standard method of physical tests for hydraulic cement.”


110002.

• IS: 456 (2000). “Indian Standard Plain and Reinforced Concrete Code of Practice.”


110002.

• IS: 383 (1970). “Indian Standard Specification for Coarse and Fine Aggregates from

Natural Sources for Concrete (Second Revision).” Bureau of Indian standards,

Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002.


39 | P a g e

• IS: 10262 (1982) (Reaffirmed 2004). “Recommended Guidelines for Concrete Mix


110002.

• IS: 13311 (part -1) (part -2) (1992). “Indian Standard Methods Non-destructive

testing of Concrete-methods of test.” Bureau of Indian standards, Manak Bhavan, 9

Bahadur Shah Zafar Marg, New Delhi 110002.

• Bakri, A. M. M. A., Fadli, S. A. S. N., M. D., Bakar, M. D. A., and Leong, K. W.,

(2007).

• “Comparison of Rubber as Aggregate and Rubber as Filler in Concrete.” 1st

international Conference on Sustainable Materials 2007, Penang.

• Fattuhi, N. I., and Clark, L. A. (1996). “Cement-based materials containing Shredded

scrap truck tyre rubber.” Construction and Building Materials, 10(4), 229-236.

• Fourier Transform Infrared Spectroscopy. http://www.siliconfareast.com/FTIR.htm

• Ganjian, E., Khorami, M., Maghsoudi, A. K. (2008). “Scrap-tyre-rubber replacement

for aggregate and filler in concrete.” Construction and Building Materials.

• Ghambhir, M. L. (2003). Concrete Technology (2nd edition), Huang, B., Li, G., Pang,

S., and Eggers, J., (2004). “Investigation into Waste Tire Rubber- Filled Concrete.”

Journal of Materials in Civil Engineering, 16(3), 187-194.

• Hernandez-Olivares, F., Barluenga, G., Bollati, M., and Witoszek, B. (2002). “Static

and dynamic behaviour of recycled tyre rubber-filled concrete.” Cement Concrete

Research, 32, 1587–1596.


40 | P a g e

• Thesis on “WASTE TYRE RUBBER AS COARSEAGGREGATE REPLACEMENT IN

CEMENT CONCRETE” presented by Mr. Kamlesh Ahirwar in IIT Kharagpur.


41 | P a g e

Mix design for M20 grade concrete in accordance to IS: 10262(1982)

1. Design Parameters

a) required at 28 days (MPa) fck 25 N/mm2

b) 28 days strength of cement 33.74 N/mm2

c) Workability 0.85 compacting factor

d) Degree of quality control Good

e) Type of exposure Mild

2. Test data for materials

a) Cement Portland pozzolana cement(31.9-36.8 N/mm2)

b) Specific gravity

a. Cement 3.15

b. Coarse aggregate 2.88

c. Fine aggregate 2.537

c) Volume of entrapped air (cum/cum of concrete) 2.0 %

d) Standard Deviation (S) (MPa) 5.3

e) Maximum size of aggregate 20mm

f) Grading zone for fine aggregate II

g) Water content per cubic meter 186

h) Sand content as percentage of total 35.00

aggregate by absolute volume


42 | P a g e

3. Target Mean Strength of Concrete

For a tolerance factor of 1.65, the target mean strength for the specified

Characteristics cube strength is as below:

Ft= Fck+st

= 25 + 1.65 x 5.3

= 27.6 N/mm2

4. Selection of Water Cement Ratio

From figure 2 of the IS: 10262(1982),

The water cement ratio = 0.42

5. Selection of Water Content and Fine to Total Aggregate Ratio

[From table 4 of the IS: 10262(1982)]

For 20 mm nominal maximum size of aggregate and sand conforming to grading of zone II.

Water content per cubic meter = 186 Kg/m3

Cement = 186/.42= 442.857 Kg/m3

Sand content as percentage of total aggregate by absolute volume = 35

6. Calculation of Aggregate Content

Absolute volume of fresh concrete (V) = Gross volume – volume of entrapped air

V = 1- 0.02 = 0.98 %

For fine aggregate

V=(W+C/Sc+(1/p)Fa/Sfa)x 1/1000

For Coarse Aggregate

V=(W+C/Sc+(1/1-p)Ca/Sca)x 1/1000


43 | P a g e

Where

V = Absolute volume of fresh concrete.

W= Mass of water kg/m3 of concrete.

C= Mass of concrete kg/m3 of concrete

Sc= Specific gravity of cement.

P= Ratio of fine aggregate to total aggregate by volume.

Fa, Ca = Total masses of fine aggregate and coarse aggregate kg/m3 of concrete

respectively.

Sfa, Sca = Specific gravities of saturated surface dry fine aggregate and coarse aggregate

respectively

From Above Formulas.

Fa=594.603 Kg/m3

Ca=1104.408 Kg/m3

Mix proportion

Water Cement Fine aggregate Coarse aggregate

Weight (Kg/m3) 186 442.408 594.603 1104.408

Ratio .42 1 1.34 2.49


44 | P a g e

Thank You

Date post:	27-Dec-2015
Category:	Documents
Upload:	harish-ashok-sharma
View:	20 times
Download:	1 times

Rubberized Cocrete

Documents