WASTE PLASTIC BOTTLE CAP POLYPROPYLENE (PP) AS ...

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WASTE PLASTIC BOTTLE CAP POLYPROPYLENE (PP) AS COARSE AGGREGATE REPLACEMENT IN CONCRETE TAN SOON TECK Thesis submitted in fulfilment of the requirements for the award of the degree of B. Eng (Hons.) Civil Engineering Faculty of Civil Engineering and Earth Resources UNIVERSITI MALAYSIA PAHANG JUNE 2015

Transcript of WASTE PLASTIC BOTTLE CAP POLYPROPYLENE (PP) AS ...

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WASTE PLASTIC BOTTLE CAP POLYPROPYLENE (PP) AS COARSE

AGGREGATE REPLACEMENT IN CONCRETE

TAN SOON TECK

Thesis submitted in fulfilment of the requirements

for the award of the degree of

B. Eng (Hons.) Civil Engineering

Faculty of Civil Engineering and Earth Resources

UNIVERSITI MALAYSIA PAHANG

JUNE 2015

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ABSTRACT

Polypropylene (PP) has been widely used by researchers to determine its

performance in concrete matrix. Generally, PP will be crushed or reshaped into flakes,

fibres or granular shapes. However, the cost and time consumption for processing will

increased as the melting point of PP is around 170 oC. Hence, the novelty of this

research was to determine the suitability of the polypropylene cap (without any

alteration of shape) as coarse aggregate replacement in concrete. The results of slump

test, rebound hammer test and compressive strength test shows that the PP cap were

suitable to be replaced as coarse aggregate in concrete. The compressive strength of

concrete with PP cap was 27.3 MPa, higher than 20 MPa which is suitable for general

concrete work. Furthermore, the compressive strength results of concrete elevated to

temperatures (100, 200, 300 and 600 oC) at the age of 28 days were also studied. From

100 oC to 300

oC, the results indicated that concrete with PP cap performed better than

the control concrete. The coarse aggregate replaced by PP cap was fixed to 10 %. Based

on the experimental results, It was concluded that the PP cap aggregates were suitable to

replace as coarse aggregate in concrete.

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ABSTRAK

Polypropylene (PP) telah digunakan secara meluas oleh penyelidik untuk

menentukan prestasi dalam matriks konkrit. Secara umumnya, PP akan dihancurkan

atau membentuk semula ke dalam kepingan, gentian atau bentuk berbutir. Walau

bagaimanapun, penggunaan kos dan masa untuk diproses akan meningkat kerana titik

lebur PP adalah sekitar 170 oC. Oleh itu, sesuatu yang baru daripada kajian ini adalah

untuk menentukan kesesuaian topi polypropylene (tanpa apa-apa pengubahan bentuk)

sebagai pengganti agregat kasar dalam konkrit.Keputusan ujian kemerosotan, ujian

tukul pantulan dan ujian kekuatan mampatan menunjukkan bahawa topi PP adalah

sesuai untuk digantikan sebagai agregat kasar dalam konkrit. Kekuatan mampatan

konkrit dengan PP topi adalah 27.3 MPa, lebih tinggi daripada 20 MPa yang sesuai

untuk kerja-kerja konkrit umum.Tambahan pula, keputusan kekuatan mampatan konkrit

dinaikkan kepada suhu (100, 200, 300 dan 600 oC) pada usia 28 hari juga telah dikaji.

Dari 100 oC hingga 300

oC, keputusan menunjukkan bahawa konkrit dengan PP topi

prestasi yang lebih baik daripada konkrit kawalan. Agregat kasar digantikan oleh PP

topi ditetapkan kepada 10 %. Berdasarkan keputusan eksperimen, Ia telah membuat

kesimpulan bahawa PP agregat penutup adalah sesuai untuk digantikan sebagai agregat

kasar dalam konkrit.

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TABLE OF CONTENTS

Page

SUPERVISOR’S DECLARATION ii

STUDENT’S DECLARATION iii

ACKNOWLEDGEMENTS v

ABSTRACT vi

ABSTRAK vii

TABLE OF CONTENTS viii

LIST OF TABLES xi

LIST OF FIGURES xiii

LIST OF SYMBOLS xv

LIST OF ABBREVIATIONS xvi

CHAPTER 1 INTRODUCTION

1.1 Background 1

1.2 Problem Statement 3

1.3 Research Objectives 4

1.4 Scope of Study 4

1.5 Significant of Study 5

CHAPTER 2 LITERATURE REVIEW

2.1 Concrete 6

2.1.1 Cement 7

2.1.2 Aggregate 10

2.1.3 Superplasticizer 11

2.1.4 Durability 11

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2.1.5 Workability 12

2.2 Properties of Polypropylene 13

2.3

2.4

Mechanical Properties of Concrete with Polypropylene cap as

Coarse Aggregate

Mechanical Properties of Concrete with Polypropylene cap as

Coarse Aggregate after Exposed to Elevated Temperature

14

16

2.5 Conclusion 17

CHAPTER 3 RESEARCH METHODOLOGY

3.1 Materials 18

3.1.1 Ordinary Portland Cement 19

3.1.2 Fine Aggregate 19

3.1.3 Coarse Aggregate 20

3.1.4 Water 21

3.1.5 Superplasticizer 21

3.2 Preparation of Polypropylene Cap 21

3.3 Concrete Composition Design 23

3.4 Casting, Molding and Demoulding of the Specimens 25

3.5 Curing 26

3.6 Test for Fresh Concrete 27

3.6.1 Slump Test 28

3.6.2 Consistency Test 29

3.7 Destructive Test 30

3.7.1 Compressive Strength Test 30

3.7.2 Compressive Strength Test of Specimens Exposed to 32

Elevated Temperature

3.8 Non Destructive Test 32

3.8.1 Rebound Hammer Test 33

3.9 Conclusion 34

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CHAPTER 4 RESULTS AND DISCUSSIONS

4.1 Pre-Mixing Test 35

4.1.1 Sieve Analysis 35

4.2 Fresh and Hardened Concrete Test 42

4.2.1 Slump Test 42

4.2.2 Consistency Test 45

4.2.3 Compressive Strength Test 48

4.2.4 Rebound Hammer Test 49

4.2.5 Compressive Strength Test of Concrete Exposed to Elevated 50

Temperature

CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS

5.1 Conclusions 56

5.2 Recommendations 57

REFERENCES 58

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LIST OF TABLES

Table No. Title Pages

1.1 Types and quantities of plastic in municipal solid waste in USA 2

2.1 Concrete Grade and Usage 7

2.2 Chemical composition of OPC 8

2.3 Standards and specifications of cement in Malaysia 9

3.1 Degree of workability, slump and compacting factor 29

4.1 Coarse aggregate sieve test 1 36

4.2 Coarse aggregate sieve test 2 36

4.3 Coarse aggregate sieve test 3 37

4.4 Fine aggregate sieve test 1 37

4.5 Fine aggregate sieve test 2 38

4.6 Fine aggregate sieve test 3 38

4.7

Fineness modulus of coarse aggregate and fine aggregate

39

4.8 Aggregate size in typical applications 40

4.9

Fineness modulus of different types of sand

41

4.10

Slump test result for different types of concrete

43

4.11

Degree of workability, slump and compacting factor

44

4.12

Compressive strength of different types of concrete

45

4.13

Compressive strength of different types of concrete on 7, 14 and 28

Days

48

4.14

Compressive strength and surface strength of concretes

49

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4.15 Residual compressive strength of concrete after exposed to elevated

temperature

51

4.16

Weight loss of the concrete

53

4.17

Summary results of all test

55

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LIST OF FIGURES

Figure No. Title Pages

1.1 Compressed bales of waste plastic bottles 2

3.1 Ordinary Portland Cement 19

3.2 River Sand 20

3.3 Natural granite 20

3.4 Polypropylene cap with hole, puncher and hammer 22

3.5 Volume of water displaced by polypropylene caps and coarse

aggregate in measuring cylinders

23

3.6 Concrete mix design form 24

3.7 100 x 100 x 100 mm cube mold 25

3.8 Mixing processes of polypropylene cap as partial coarse aggregate

replacement

26

3.9 Cube specimens undergoing curing process 27

3.10 Types of slump 28

3.11 Equipment for slump test 29

3.12 Compressive test machine 31

3.13 Satisfactory failures of concrete 31

3.14 Unsatisfactory Failures of concrete 31

3.15 Rebound hammer 33

3.16 Compressive strength estimation chart 34

4.1 Grading curve of coarse aggregate 39

4.2 Grading curve of fine aggregate 41

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4.3 Comparison of slump for different types of concrete 43

4.4 Zero slump of PP0 concrete 44

4.5 True slump of PP0 concrete 44

4.6 Compressive strength of PP0 on day 7 45

4.7 Compressive strength of PP0 on day 14 46

4.8 Compressive strength of PPA on day 7 46

4.9 Compressive strength of PPA on day 14 46

4.10 Compressive strength of PPB on day 7 47

4.11 Compressive strength of PPB on day 14 47

4.12 Compressive strength of concretes 48

4.13 Compressive strength of concrete by compressive test and rebound

hammer test

50

4.14

Relative residual compressive strength after exposed to elevated

temperature

51

4.15

Weight loss of concrete

53

4.16

PPB concrete exposed to 100°C

54

4.17

PPB concrete exposed to 200°C

54

4.18

PPB concrete exposed to 300°C

54

4.19

PPB concrete exposed to 600°C

54

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LIST OF SYMBOLS

% Percentage

mm Millimeter

N/mm2

Newton per millimeter square

kg Kilogram

N Newton

°C Degree Celsius

∑ Sum

w/c Water to cement ratio

mm2

Millimeter square

MPa Mega Pascal

± Plus-Minus

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LIST OF ABBREVIATIONS

ASTM American Society for Testing and Materials

BS British Standard

CEM Certified Energy Manager

EN European Standards

MS Malaysia Standard

NA Natural Aggregate

OPC Ordinary Portland Cement

PP Polypropylene

PP0 Concrete without polypropylene cap

PPA Concrete with polypropylene cap

PPB Concrete with polypropylene cap with hole

PET Polyethylene Terephthalate

RILEM Reunion International Laboratories Experts Material

YTL YTL Corporation Berhad

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CHAPTER 1

INTRODUCTION

1.1 Background

Quantities of plastic wastes has increased rapidly throughout this decade due to its

beneficial properties of low density, light weight and strength. Other important factors such

as low cost and friendly design were the reason polymer product becomes an inseparable

part of our lives. The one of the most profitable industry in Malaysia was plastic

manufacturing. The exports of plastic products from Malaysia to South East Asia, United

Kingdom and United State in 2001 were valued at U.S. $1.83 billion (Malaysia Department

Statistics, 2002).

In Malaysia, most of our plastic wastes were dispose or abandon and not recycle. In

other words, inside the municipal waste stream, the plastic wastes management options

were merely incinerated or landfill. This had caused a very serious environmental threat to

the environment due to the high volume of municipal solid wastes. The world's annual

usage of plastic material has growth from approximately 5 million tons in 1950s to almost

100 million tons in 2001. This tremendous growth of plastic waste should concern to

reduce the environmental pollution. Figure 1.1 presents the types and quantities of plastic in

municipal solid waste in United States of America (Siddique et al, 2008). Other than that,

with the increasing cost of space for landfill and scarcity of natural aggregate, waste

utilization has become a desirable alternative to disposal.

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Table 1.1: Types and quantities of plastic in municipal solid waste in USA

(Subramanian, 2000)

Plastic bottle cap which is made of polypropylene (PP) is one of the plastic product

also known as low modulus synthesis fibers that are effectual in controlling shrinkage

cracking (Foti, 2011). Polypropylene cap is a hard but flexible plastic while the body of

plastic bottle is made from polyethylene terephathalate (PET), a clear tough plastic

(Siddique et al, 2008). Unlikely to PET, the polypropylene cap is excluded in the process of

recycling bottle due to its high melting point. The difference of polypropylene cap versus

polyethylene terephathalate bottle in melting point is approximately 100 degree Celsius,

which dramatically increases the cost of processing polypropylene cap. Obviously, the

polypropylene cap was eliminated from selection of recycled due to its value in the market

(Garthwaite, 2008).

Figure 1.1: Compressed bales of waste plastic bottles

Type of plastic Quantity (1000 tons)

Polyethylene terephthalate (PET) 1700

High density polyethylene (HDPE) 4120

Low density polyethylene (LDPE)

Polypropylene (PP)

Polystyrene (PS)

Other

5010

2580

1990

3130

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Incorporate with this situation, the purpose of this study was to fully utilize the

polypropylene cap as partial coarse aggregate replacement in concrete in order to provide a

desirable alternatives in reduce the negative impact on environment, producing a new

composition of concrete and at the same time deplete the pressure on exploit natural

resources. Furthermore, the polypropylene cap can greatly improve some of concrete

properties due to polypropylene cap has high toughness, lighter in weight and good

abrasion behavior (Saikia & Brito, 2012).

1.2 Problem Statement

The production and consumption of plastic has increases substantially worldwide in

recent years and has created a huge deposit in the domestic wastes and landfills. For

example, around 32 million tons of plastic-based wastes were produced in the year of 2012.

However, the rate of recycling plastic bottle was only 31% and the remaining was sent to

landfill or incinerate (EPA, 2014). Despite the fact of increasing cost for landfill,

polypropylene cap required a significant amount of time, approximately up to hundreds of

year to be fully decomposed (to be determined because polypropylene cap have not existed

for long enough) due to its very slow degradation rate. At the same time, incineration was

also not an advisable option due to the potentially harmful chemical composition of

polypropylene cap (Siddique et al, 2008).

On the other hand, high demands for raw materials such as natural aggregate due to

the rapid increasing of population and construction development has cause a heavy

exploitation on the natural resources. Continuous of natural aggregate quarrying produced

issues like damaging the environment and depleting fast, causing a shortage in natural

aggregate. Thus, comprising the negative environment impact of polypropylene cap and the

depletion of natural aggregate, utilize waste polypropylene cap as partial aggregate

replacement in concrete has foreseen to become considerably effective solution for these

issues. The development of polypropylene cap aggregate as construction materials are

important to both the construction and plastic bottle recycling industry as it is essential to

preserves our depleting natural resources.

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1.3 Research objectives

It is a tremendous achievement for both the construction and the plastic recycling

industries if the polypropylene cap can be used to replace the natural aggregate. The

objectives of the study are:

To determine the suitability of polypropylene cap as partial coarse aggregate

replacement in concrete.

To compare the mechanical properties of polypropylene cap concrete with control

concrete.

To study the effect of hole in polypropylene cap as partial coarse aggregate

replacement.

To study the effect of elevated temperature on the mechanical properties of

polypropylene cap concrete and control concrete.

1.4 Scope of work

In general, the coarse aggregate used in concrete production should be hard, dense,

no harmful chemicals and durable. However, the composition of plastic bottle may be

varies in size, hardness, shape and chemical composition. Therefore, only the mineral water

PP plastic bottle caps are chosen as coarse aggregate replacement.

Other scopes of study are as follow:

3 types of composition are be used to produce the concrete, the first type is PP0

which is the control concrete without any replacement of polypropylene cap. The

second concrete is PPA which is the plastic concrete with 10% replacement of

polypropylene cap as coarse aggregate by volume. The last one is the PPB which is

also the similar plastic concrete with 10% replacement of polypropylene cap.

However, the polypropylene cap for PPB has a hole punch through by a puncher

and hammer manually.

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The mix design of grade 30 concrete has been developed using polypropylene cap,

crushed granite,river sand, Ordinary Portland Cement and tap water.

The consistency test was carried out to ensure that the mix design was adequate to

produce a grade 30 concrete.

The 100 x 100 x 100 mm sized cube has been chosen as the dimension of cube for

destructive test.

The specimens were being tested at the age of 7, 14 and 28 days with according to

the standard recommendation (BS 1881).

The concrete properties can be obtained by carry out the destructive and non-

destructive tests such as slump test, compressive test, density test, rebound hammer

test, fire resistance and consistency test.

1.5 Significance of the study

The adoption of polypropylene cap as replacement of coarse aggregate will bring

significant impacts on the environment and society. The significance of the studies are state

as follow:

To reduce the space required for the landfill of polypropylene cap.

To diminish the pressure on exploiting the natural resources.

To introduce the potential of polypropylene cap as coarse aggregate.

In terms of novelty, the success achievement of the research was not only produce a new

composition of plastic concrete but also lower the production cost of the concrete. This

would contribute greatly in the construction industry as well as reduce the negative

environment impact. In addition, the applicability of the new concrete in the construction

industries was considered as a huge leap as the strength of concrete more than 30N/mm2

was feasible in structural work.

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CHAPTER 2

LITERATURE REVIEW

Literature review is a chapter that reviews the study and reading made to the related

topic. It is a synthesis and analysis of particular relevant published work, journal and

proceeding, relating all the times to the purpose of this research study and rationale. In this

chapter, the properties and composition of the concrete as well as the component inside will

be discussed. Since the topic is related to polypropylene cap, the properties of it are pointed

out in this chapter. Furthermore, the strength of the concrete with polypropylene cap

replacement as coarse aggregate are also discussed.

2.1 Concrete

Concrete which has greater properties like better versatility, availability and

economy compared with the other structural materials are one of the vital materials for

structures and been widely used worldwide. Almost all structural in construction such as

building, houses, dams, retaining walls, bridges, ports, etc are made with concrete

(Beycioglu & Yılmaz, 2014). The main component of concrete is comprised of cement,

water, fine and coarse aggregate. According to Hanssanpour et al. (2012), concrete is a

brittle structure just like glass and it has low tensile strength and shear capacity. Hence the

brittleness of the concrete is increased with the increase of strength in concrete. Thus,

leading the concrete yields to cracking. However, studies of fiber reinforced concrete had

shown as an alternative solution for this problem.

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In this study, polypropylene cap concrete is expected to perform better than normal

concrete in terms of ductility and toughness. Polypropylene cap as known as synthetic fiber

are claims to be more effective in the post-crack phase of concrete due to its "sewing

effect". The effect of the fiber acts on the crack of the concrete is similar to a bridging

created between the cracks of the concrete. Thus, increased the ductility and toughness of

the concrete (Foti, 2011). Table 2.1 represents the concrete usage with respects to its

concrete grade.

Table 2.1: Concrete Grade and Usage

Concrete Grade

( N / mm2 )

Ratio of Cement, Sand

and Aggregate

Usage

10 1 : 4 : 8 Blinding Concrete

15 1 : 3 : 6 Mass Concrete

20 1 : 2.5 : 5 Light Reinforce Concrete

25 1 : 2 : 4 Reinforce Concrete

30 1 : 1.5 : 3 Heavy Reinforced Concrete Pre-cast

35 1 : 1.5 : 2 Pre-stress Concrete/Pre-cast

40 1 : 1 : 1 Very Heavy Reinforced Concrete Pre-

Stress/Pre-cast

2.1.1 Cement

According to Paraside and Prochorov (1979), cement is the general term for a

classification of factitious, inorganic, powered, mainly hydraulic binding materials. After

the interaction with water, fluid solutions of salts, or other aqueous, they form a pliant mass

that solidify with time and becomes a hardened solid, rocklike body. Cement can be

claimed as one of the most essential materials in construction and it is mainly used to make

concrete and mortar.

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According to Portland Cement Association, (2010), one of the most common

hydraulic cement is Ordinary Portland Cement. The history of Portland Cement can be

simplified as

In 1976, John Smeaton was the first to understand the chemical properties of cement.

In 1824, James Parker and Joseph Aspdin were the first to carry the patent for

Portland cement and it was filed in England. The Portland cement is made by

burning powdered limestone and clay.

In 1845, Isaac Johnson made a prototype of modern cement with burning mixture of

clay and chalk.

The chemical composition of Ordinary Portland Cement (OPC) are as shown in the

Table 2.2.

Table 2.2: Chemical composition of OPC

Component Composition (%)

Tricalcium Silicate 50

Dicalcium Silicate 25

Tricalcium Aluminate 10

TetracalciumAluminoferrite 10

Gypsum 5

The quality of Ordinary Portland Cement is assured and Table 2.3 represents the

Standards and Specification of Cement in Malaysia. In this study, OPC will be chosen as

the cement for all mixing concrete as it is common and widely available.

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Table 2.3: Standards and Specifications of Cement in Malaysia (Malaysia Standard

Specification of Cement, 2014)

Main

Type

Notation

Clinker

Content

(%)

Content of other

Main Constituents

(%)

CEM I Portland Cement CEM I 95-100 0-5

CEM II

Portland - Slag Cement CEM II/A-S 80-94 6-20

CEM II/B-S 65-79 21-35

Portland-silica fume

Cement

CEM II/A-D 90-94

6-10

Portland-Pozzolanic

Cement

CEM II/A-P 80-94 6-20

CEM II/B-P 65-79 21-35

CEM II/A-Q 80-94 6-20

CEM II/B-Q 65-79 21-35

Portland-fly ash cement CEM II/A-V 80-94 6-20

CEM II/B-V 65-79 21-35

CEM II/A-W 80-94 6-20

CEM II/B-W 65-79 21-35

Portland-burnt shale

cement

CEM II/A-T 80-94 6-20

CEM II/B-T 65-79 21-35

Portland-limestone

cement

CEM II/A-L 80-94 6-20

CEM II/A-LL 80-94 6-20

CEM II/B-L 65-79 21-35

CEM II/B-LL 65-79 21-35

Portland-composite

cement

CEM II/A-M 80-94 6-20

CEM II/B-M 65-79 21-35

CEM III

Blast furnace cement CEM II/A 35-64 36-65

CEM II/B 20-34 66-80

CEM II/C 5-19 81-95

CEM IV Portland fly ash cement CEM IV/A 65-89 11-35

Pozzolanic fly ash

cement

CEM IV/B 45-64 36-55

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CEM V Composite cement CEM V/A 40-64 36-60

CEM V/B 20-38 62-80

2.1.2 Aggregate

Aggregates are granular materials are granular materials such as natural gravels,

sands and crushed stones. It's a material of various sizes and shapes, it's also one of the

important material used in producing concrete. Generally, aggregate occupy 70-80% of the

concrete volume and have significant influence on the properties of concrete. Thus, it

should be strong and hard, free from undesirable impurities, chemically stable and durable.

The suitability of aggregate for concrete are depending on the concrete design limitation, to

secure the quality of the concrete, both fine and coarse aggregate need to be quality sized

before applying in accordance with the Standards required (Yunusa, 2011).

Generally, aggregate can be categories as fine aggregate or coarse aggregate. The

size of fine aggregate in concrete construction are normally smaller than 4.75 mm and

equal or larger than 75 µm. While the coarse aggregate are with particle size equal to or

larger than 4.75 µm. The main functions of aggregate are to reduce the cost of concrete,

produce workable yet cohesive concrete, reduce the heat of hydration of concrete, reduce

the shrinkage of concrete (Lamond & Pielert, 2006).

According to Farrag and Yehia (2014), there are various effect of aggregate on the

concrete and it is as followed:

In terms of absorption, the aggregate may affect the effective mixing water and thus

reducing the compressive strength and durability. Hence, aggregates are pre-soaked

or pre-wetted with water in order to achieve saturated surface dry state.

In terms of specific gravity factor, it is depending on the internal structure of

aggregates. Generally, aggregates with specific gravity factor more than 1.3 can be

used to produce high strength concrete..

In terms of density, aggregates will significantly affects the mechanical and

durability of the concrete. Typically, high dense concrete mixes are made from high

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bulk density aggregates and packing density is very vital in enhancing durability

features and creates a uniform microstructure.

In terms of shape, angular aggregates are helpful in achieving well packed concrete

mixes thus resulting in high strength. In contrast with that, round aggregates do not

contribute to lower workability as opposed to angular aggregates.

In this study, the fine and coarse aggregate are natural gravel and river sand

respectively.

2.1.3 Superplasticizer

According to U.S. Department of Transportation (2014), superplasticizers also

known as high range water reducer is use to achieve flowing concrete with high slump in

the range of 175-225mm. It's normally used in heavily reinforced concrete and situation

where appropriate consolidation by vibration cannot be easily achieved. Other than that,

superplasticizers are able to reduce the water requirements up to 12-25% without affecting

the workability of the concrete and lower the permeability.

The main intention of using superplasticizer is to increase the cement paste fluidity,

with the superplasticizer the water required can be reduced. Since the high water to cement

ratio will decrease the strength and durability of the concrete (Zheng & Sui, 2009).

2.1.4 Durability

According to Monteiro et al. (2009), durability of a concrete is defined as the ability

to resist chemical attack, abrasion, weather action, or any deterioration. Similarly, the

Portland Cement Association, (2010) also states that durability of a concrete is the ability to

last a long time without significant deterioration. The durability of the concrete will not

only affect the life span of the concrete but also affect the environment. A durable material

helps in preserving the natural resources and decreases the wastes to the environment. The

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environmental issues such as depletion of natural resources and pollution from construction

wastes can be reduced.

According to Ramezanianpour et al. (2013), polypropylene fibers are able to

increase the resistance of the concrete to the ion penetration which is the salt attack with

rapid chloride penetration test (RCPT).

2.1.5 Workability

Siddique et al. (2008) defines that the workability of concrete is the ease that

concrete can be mixed, moved, placed and finished simply without segregation. The slump

test, K-test and inverted slump cone can beused fordetermining the workability of concrete.

Slump test is used widely at the site to determine the workability of the concrete. The mold

for slump test is a frustum of cone, 305 mm high and it is carried out per ASTM C 143-78.

The concrete is filled in the cone and then lifted slowly, the concrete is then slump due the

removal of supporting cone. The difference in height of concrete is called slump.

Bayasi and Zeng (1993) studied the effects of polypropylene fibers on both the

slump and inverted slump cone tests of the concrete mixes. They reported there is an

increase in the inverted slump cone time and for the fiber volume fractions that are less than

or equal to 0.3%, fiber does not show any significant effect on the workability of fresh

mixed concrete and the results are rather inconsistent. However, the polypropylene fiber

shows a more obvious effect with the 19 mm fibers compared with the 12.7 mm fibers. It

can be concluded that in their studies, the workability of the concrete is improved with the

longer fibers. However, the mix ability of the concrete becomes more difficult.

According to Al-Manaseer and Dalal (1997), the slump is increased with the

incorporation of plastic aggregate in the concrete. The concrete comprised of 50% plastic

aggregates appears to have a higher cone slump compared with the concrete without plastic

aggregates. Due to the almost non-absorptive properties of plastic aggregates, the concrete

tend to have more free water and thus increases the slump.