project for using different sizes of coarse aggregate for concrete strength

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

TO STUDY THE EFFECT OF SIZES AND SHAPES OF

COARSE

AGGREGATE

ON

COMPRESSIVE

STRENGHT OF CONCRETE

Submitted by Name No. 1. Ali

Roll

(Group

Imdad Leader)

12CE05 2. Baig

Shah

12CE07

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

3. Baker

Shah Hussain

12CE10 4. Bagar

Shah

12CE11 5. Aziz

Sartaj

12CE35 6. r

Zahoo Ahmed

12CE45

Session 2012-13 Supervised by DR. SALAH UDDIN Department of Civil Engineering BALOCHISTAN UNIVERSITY OF ENGINEERING AND TECHNOLOGY KHUZDAR

CHAPTER 1: INTRODUCTION.................................................................................1 1.1

Background.................................................................................................... 1

1.2

Aim of Project................................................................................................ 2

1.3

Objective of project........................................................................................2 1.4 Scope of Project……………………………………………………………..2

1.5

Thesis structure.............................................................................................. 3

CHAPTER 2: LITERATURE REVIEW...................................................................... 4 2.1

Introduction.................................................................................................... 4

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

2.2 2.3

Concrete…………………………………………………………………… … Coarse Aggregate........................................................................................... 4 2.3.1

Size of coarse aggregate..........................................................................5

2.3.2

Shape of coarse aggregate.......................................................................6

CHAPTER 3: METHODOLOGY................................................................................ 7 3.1

Materials Collection and Testing....................................................................7 3.1.1

Cement.................................................................................................... 7

3.1.2

Water.......................................................................................................8

3.1.3

Coarse aggregate.....................................................................................8 3.1.4 Fine aggregate………………………………………………………….8

3.2

Sample shape and size....................................................................................9

3.3

Test specimen.................................................................................................9

3.4

Preparation of specimen…………………………………………………… 10

3.5

Curing of specimen...................................................................................... 10 3.6 Testing of specimen………………………………………………………..10

CHAPTER 1

INTRODUCTION 1.1 Background Different modification in concrete such as using different shapes and sizes of coarse aggregate, admixtures etc. have been used to improve the compressive strength of concrete. Using different shapes and sizes of coarse aggregate have been an interesting and innovative area of modern technique to improve the compressive strength of concrete. To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

Concrete is being consumed on large scale, it is being used for construction of massive structures such as dams, apartment blocks, bridges, tunnels, sewerage systems, pavement, roads and runways, multi-story building and more. In order to increase compressive load bearing capacity and life span of these civil engineering structure the compressive strength of concrete should be enhanced. In this regard, the sizes and shapes of coarse aggregate greatly influence the compressive strength of concrete. The sizes and shapes of coarse aggregate not only increase the compressive strength but also effect the economy such as using large coarse aggregate typically lower the cost of concrete mix by reducing the cement requirements, the most costly ingredients. In this project, different sizes (3/4” and 0.5”) and shapes (angular and rounded) of coarse aggregates were used with cement, fine aggregate (sand) and water to study the effect on compressive strength of concrete with 28 days curing. Concrete was prepared in four batches using constant mix ratio 1:2:4 with water-cement ratio of 0.5 in civil engineering laboratory. Out of four batches, two batches consist of different sizes of coarse aggregate using ¾” and 0.5” sizes and the other two batches consists of different shapes using angular and rounded shapes. Each batch consists of 4 cylinders. Compressive strength test of the cylinders will be

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

carried out according to the specification of ASTM C39/C39M-12a, in Civil Engineering Department BUET Khuzdar.

1.2 Aim of project The Aim of this project is to check out how coarse aggregate size and shape influences the compressive strength of normalconcrete.

1.3

Objectives of project The variables of this research are as follows;

1) To study the effect of compressive strength of normal-strength concrete using different sizes of coarse aggregates. 2) To study the effect of compressive strength of normal-strength concrete using different shapes of coarse aggregates.

1.4 Scope of project The limitations of this project are as follows: 1) 2) 3) 4) 5) 6)

Using Using Using Using Using Using

different sizes of coarse aggregates. different shapes of coarse aggregates. fine aggregate (sand) from a single source. mix ratio of 1:2:4. constant water-cement ratio of 0.5. ASTM guidelines for compressive Strength test on

cylindrical specimen

1.5 Thesis structure The thesis is organized as follows:

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

Chapter 1 gives the background, aim, objectives, scope of the research. Chapter 2 provides an overview of the literature on historic background of concrete, its invention and its usages, and advantages of using coarse aggregates with different sizes and shapes, and review of other past research works on shapes and sizes of coarse aggregate from other researchers. Chapter 3 discusses the methodology. It describes materials collection and testing, sample shape and size, test specimen, preparation of specimen (cylinder), curing of specimens, and testing of specimen.

CHAPTER 2

LITERATURE REVIEW 2.5 Introduction Different shapes and sizes can be used to increase the normal compressive strength of the concrete. Aggregate Shapes and sizes have their unique advantages for an instant angular shape provide greater interlocking between the particles and the rounded provided greater workability a larger aggregate size

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

produce low compressive strength in concrete compared to the concrete containing small aggregates (Bloem and Ganor, 1963). Increasing in aggregate size from 10 to 64mm result in decrease the compressive strength by 10% (Walker and Bloem) and rounded

aggregate

is

more

workable

but

have

a

lesser

compressive strength than angular( Young and Sam, 2008). As we are concerned with the compressive strength of concrete using different size and shape of coarse aggregate so literature review focuses on history of concrete, its invention and more importantly past research on sizes and shapes of coarse aggregate.

2.2 Concrete Concrete

is

composite

material,

consist

of

three

major

components Portland cement, water and aggregate. It is one of the most widely used construction materials in the world. Its worldwide consumption is over ten billion tons per year, which means, each person on earth consumes more than 1.7 ton of concrete per year. It is more than ten times of consumption by weight of steel. (1) Concrete was used by the ancient Romans in the construction of walls and roofs, but concrete has its first modern record as early as 1760, when in Britain John Smeaton used it in the first lock on

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

the river Calder. The walls of the lock were made of stone filled in with concrete. In 1796, J. Parker rediscovered the Roman natural cement, and 15 years later Vicat burned a mix of clay and lime to produce cement. In 1824, Joseph Aspdin manufactured Portland cement in Wakefield, Britain. It was called Portland cement because when hardened it resembled stone from the quarries of the Isle of Portland. (2) Neville, 1981, rightly observed that concrete is among the most commonly

used

structural

materials

alongside

steel.

The

knowledge of the properties of concrete makes possible the selection of a more suitable economic mix. The strength of the concrete is of essence. It is the maximum load (stress) that the concrete can carry (Jackson and Ravindra, 1996) . As the strength of concrete increases, its other properties usually improve. Tests for strength, particularly in compression, are easily performed; concrete

compressive

strength

is

commonly

used

in

the

construction industry for the purpose of specification and quality control. The Engineer knows his target flexural strength and will express it in terms of compressive strength. Several factors affect the compressive strength of concrete. The coarse aggregate which is the largest component of the concrete, needs to be seriously taken into consideration as it would doubtlessly play a major role in the strength improvement of the concrete.

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

2.3 Coarse aggregate Coarse aggregate is cheaper than cement and it is therefore, economical to put into the mix as much of the former and as little of the latter as possible. But economy is not the only reason for using

coarse

aggregate.

It

confers

considerable

technical

advantages on concrete, which has a higher volume stability, strength and better durability than hydrated cement paste alone. (3)

At least three-quarters of the volume of concrete is occupied by coarse aggregate, it is not surprising that its sizes and shapes is of considerable importance. Not only

the aggregate limit the

strength of concrete, as the size and shapes of coarse aggregate greatly influence the strength of concrete. (4

2.3.1 Size of coarse aggregate Walker and Bloem (1960) studied the effects of coarse aggregate size on the properties of normal-strength concrete. Their work demonstrates that an increase in aggregate size from I0 to 64 mm results in a decrease in the compressive strength of concrete, by as much as 10 percent; however, aggregate size seems to have negligible effects on flexural strength. The study also shows that the flexural-to compressive strength ratio remains at

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

approximately

12

percent

for

concrete

with

compressive

strengths between 35 MPa (5,100 psi) and 46 MPa (6,700 psi). (5) Bloem and Gaynor (1963) studied the effects of size and other coarse aggregate properties on the water requirements and strength of concrete. Their results confirm that increasing the maximum aggregate size reduces the total surface area of the aggregate,

thus

reducing

the

mixing

water

requirements;

however, even with the reduction in water, a larger size aggregate still produces lower compressive strengths in concrete compared to concretes containing smaller aggregate. Generally, in lower strength concretes, the reduction in mixing water is sufficient to offset the detrimental effects of aggregate size. However, in high-strength concretes, the effect of size dominates, and the smaller sizes produce higher strengths. (6)

2.3.2 Shape of coarse aggregate The particle shapes of a coarse aggregate influence the properties of freshly mixed concrete more than the properties of hardened concrete. Angular particles require more water to produce workable concrete than do rounded aggregates. Hence, aggregate particles that are angular require more cement to maintain

the

same

water

cement-ratio.

However,

with

satisfactory gradation, both crushed and non-crushed aggregates (of the same rock types) generally give essentially the same To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

strength for the same cement factor. The bond between cement paste and a given aggregate generally increases as particles change from smooth and rounded to rough and angular. This increase in bond is a consideration in selecting aggregates for concrete where high compressive strength is needed. (7) The strength of concrete is its major characteristic. Neville, 1981 stated that aggregates are inert materials that are dispersed through-out the cement paste whose strength depends majorly on its shape, surface texture, and cleanliness. In his research findings, he published that entirely smooth coarse aggregates lowered the strength of concrete by 10% than when the aggregates were roughened. (8) Young and Sam, 2008 [14] also stated that smooth rounded aggregates was more workable but yielded a lesser compressive strength in the matrix than irregular aggregates (angular) with rough surface texture. (9)

CHAPTER 3

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

METHODOLOGY 3.2 Introduction Concrete, which is the most used construction material, has a far greater compressive strength than mortar and sand Crete of the same cement. This exceeding strength is found to be triple (or more) that of mortar. Coarse aggregates of different size and shapes, which are the interest of this study, make the difference. Two different sizes and shapes of coarse aggregates were employed in the investigation. The sizes and shapes of coarse aggregate are ¾”, 0.5” and angular, rounded respectively.

The

mix ratio and water/cement ratio adopted for the study was 1:2:4 and 0.5 respectively. Four concrete cylinders were cast for each size and shape of coarse aggregates. All cylinders were cured for 28 days. Compressive strength of concrete is the value of test strength below which not more than a prescribed percentage of the test results should fall. Therefore cylinders were tested to investigate the effect of sizes and shapes of coarse aggregates on the compressive strength of concrete. This study was carried out into following six steps: 1) 2) 3) 4) 5) 6)

Materials Collection Sample shape and size Test Specimen Preparation Of Specimen (Cylinder) Curing Of Specimens Testing of Specimen

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

3.2

Materials collection and testing

Materials along with specification, which are going to be used for this experimental program, are summarized below:

3.2.1 Cement Ordinary Port Land cement was used in this study, as it has been frequently used in previous researches. The specific gravity of port land cement is around 3.15.

3.2.2 Water Ordinary tap water, from university water supply, was used for the entire experimental work.

3.2.3 Coarse Aggregate Coarse aggregate of different shapes and sizes are used as load bearing material throughout this study. Coarse aggregate are passed through sieve no 26 and sieve no 12 to obtaine the ¾” and 0.5” sizes respectively. The sieve analysis was carried out in accordance with ASTM------------ for the coarse aggregate. Coarse

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

aggregate are obtained from Crushing Plant of Khuzdar city and Khatan river.

3.2.4

Fine aggregate

Fine aggregate was used in this investigation as filling materials which make the concrete economical. In entire project work, sand from one source was used which was purchased from local store of Khuzdar city in dry state , graded between 4.75mm (No.4) sieve and 150 µm (No.100) was used. The sieve analysis was carried out in accordance with ASTM C136 – 04 for the sand.

3.3 Sample shape and size

According

to

ASTM

C109/C109M–13

use

---in

cylindrical

specimens for compressive strength test of normal-strength concrete.

3.4 Test specimen

The mix ratio of 1:2:4 was used for different sizes and shapes of coarse aggregate for preparing test specimens using a constant water cement ratio of 0.5. For each size and shapes, 4 cylinders

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

were prepared. All the cylinders were cured for constant curing period for 28 days which are shown in table.

Shape of coarse aggregat e

Size of coarse aggregate

Angular

¾”

Rounded

¾”

Table Test specimens NO. OF MIX Cylinders for RATIO

Total No of Cylinders

CURING DAYS

4

8

28

4

8

28

each size of coarse aggregate

1:2:4 0.5” 1:2:4 0.5”

3.5 Preparation of Specimen Specimen were prepared according to ASTM-------------- as given below: 1) Cement, fine aggregates and required coarse aggregates were mixed thoroughly in concrete mixer in civil department laboratory to get a uniform color in dry state. 2) Use a water-cement ratio of 0.5 was used for cement. 3) Water was added to mix according to given specifications and mixed them thoroughly to get a workable concrete.

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

4) The cylinders of 12” x 6” were filled with three layers using vibrating machine for the well compaction of each layer. 5) The surfaces of specimen were made smooth with the help of trowel.

3.6

Curing Of Specimens

After 24 hours each specimen was removed from the mould and labeled with the date and kept in water tub for curing till 28 days at room temperature [23 ± 2 °C].

3.7 Testing of Specimen Compressive strength test of specimens will be done using compression testing machine in MT lab at Civil engineering department BUET Khuzdar. The tests on the specimens will be performed according to ASTM guidelines the compressive test on the cylinder will be done after 28 days of curing. . Maximum load is noted and stress corresponding to that force is calculated by the following formula.

σ=P/A

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete

CHAPTER CHAPTER 2. Literature 3. Methodology CHAPTER Review 1.Introduction

Where P = load in pounds (lbs.)

A = area of sample in contact with bearing of machine in “sq.in”

EFFECTS OF AGGREGATE TYPE, SIZE, AND CONTENT ON CONCRETE STRENGTH AND FRACTURE ENERGY By

Rozalija Kozul David Darwin 5,6

Aggregates for Concrete http://www.ce.memphis.edu/1101/notes/concrete/PCA_manual/Chap05.pdf

To study the effect of sizes and shapes of coarse aggregate on compressive strength of concrete