Comparative Analysis of the Compressive Strength of Concrete with Gravel and Crushed Burnt Bricks as Coarse Aggregates.

ABSTRACT The research was conducted to study the possibility of utilizing the waste bricks abundantly available in most parts of Gwer-West Local Government Area of Benue State, particularly Naka, the Local Government capital, as coarse aggregates in structural concrete. Trial mixes were prepared using the crushed burnt bricks known also as brick bats as coarse aggregates only, mixture of crushed bricks and river washed gravel as well as using river washed gravel from River Benue only at varying water-cement ratios. Cubes of concrete were prepared and tested to study the compressive strength. The results indicate that the concrete having brick bats as aggregates may be termed medium light weight concrete having a density between 2000-2200 kg/m3 . Use of broken bricks as coarse aggregate for structural concrete is recommended when natural aggregates are not easily available, high strength of concrete is not required and the bearing capacity of the soil is low. Finally Scheffe’s second degree polynomial was used to obtain a model for predicting the compressive strength of gravel-crushed burnt bricks concrete.

TABLE OF CONTENTS

Title page - - - - - - - - - - ii

Approval - - - - - - - - - - iii

Dedication - - - - - - - - - - iv

Acknowledgment - - - - - - - - - v

Table of Content - - - - - - - - - vii

List of Tables - - - - - - - - - x

List of Figures - - - - - - - - - x

Abstract - - - - - - - - - - xiii

Chapter One - - - - - - - - - 1

1.0 Introduction- - - - - - - - - 1

1.1 Research Background - - - - - - - 1

1.2 Research Problem - - - - - - - - 2

1.3 Significance - - - - - - - - - 2

1.4 Aim and Objectives - - - - - - - 3

1.5 Scope and Limitations- - - - - - - - 4

viii

Chapter Two - - - - - - - - - 5

2.0 Literature Review - - - - - - - - 5

2.1 Concrete- - - - - - - - - - 5

2.2 Cement - - - - - - - - - 6

2.3 Aggregates - - - - - - - - - 7

2.3.1 Classification of Aggregates - - - - - - 8

2.3.2 Crushed burnt bricks in Concrete - - - - - 9

2.4 Water cement ratio- - - - - - - - 11

2.5 Mix Design and Optimization - - - - - - 13

Chapter Three - - - - - - - - - 14

3.0 Materials and Methods - - - - - - - 14

3.1 Materials - - - - - - - - - 14

3.2 Methods - - - - - - - - 14

3.2.1 Sources of Data - - - - - - - - 14

3.2.2 Auxiliary Tests - - - - - - - - - 14

3.2.3 Concrete Mix Design - - - - - - - 15

ix

3.3 Model Derivation - - - - - - - - 15

Chapter Four - - - - - - - - - 23

4.0 Results, Model and Discussion - - - - - - 23

4.1 Specific Gravity (SG) - - - - - - 23

4.2 Aggregate Impact Value (AIV) - - - - - - 23

4.3 Aggregate Crushing Value (ACV) - - - - 24

4.4 Aggregate Water Absorption (AWA) - - - - - 24

4.5 Particle Size Distribution - - - - - - - 25

4.6 Slump - - - - - - - - - 28

4.7 Compressive Strength - - - - - - - 29

4.8 Model Verification- - - - - - - - 35

Chapter Five - - - - - - - - - 39

5.0 Conclusions and Recommendations - - - - - 39

5.1 Conclusions - - - - - - - - - 39

5.2 Recommendations - - - - - - - - 39

References - - - - - - - - - - 40