Effect of Crushed Concrete as Coarse Aggregates in Production of Concrete

ABSTRACT

In the face of a possible scarcity of natural aggregates in the future in line with sustainable construction, this research investigates the feasibility of the use of recycled coarse  aggregates as an alternative to natural coarse aggregates in structural concrete. The recycled coarse aggregate used in the research was processed from waste concrete. The percentage of recycled coarse aggregates by weight of all in aggregates in the test mixes were 0%, 5% 10% 20% and 30 % respectively. The properties of both natural and recycled coarse aggregates and the fresh and hardened properties of both control and trial concrete mixes were investigated. The results showed that the recycled coarse  aggregates had poor mechanical and physical properties.  Aggregate Impact Value, Aggregate Crushing Value, Compressive strength were lowered with an increase in recycle aggregate content. The recycled coarse aggregates (RCA) had little influence on the hardened density of concrete and an increase in recycled aggregate content led to a decrease in capacity.

TABLE OF CONTENTS

TITLED PAGE

CERTIFICATION                                                                                                ii

DEDICATION                                                                                                    iii

ACKNOWLEDGMENT                                                                                          iv

ABSTRACT                                                                                                        v

TABLE OF CONTENT                                                                                          vi

LIST OF TABLE                                                                                                  ix

LIST OF FIGURE                                                                                                x       

CHAPTER ONE: INTRODUCTION                                                                  

1.0 Background of the study             1

1.1 Problem Statement                                                                      2

1.2 Aim and Objectives              3

1.3 Justification of the study                                                                              4

1.4 Scope of the study                                                                                       5

CHAPTER TWO: LITERATURE REVIEW

2.0  Literature Review                                                                                                 6      

2.1 Crushed Aggregate Concrete               7 

2.2 Size Distribution                  7

2.3  Classification of Aggregate               8

2.4 Sources of crushed Aggregates                    8

2.5  Material Properties                                                                                      9

2.5.1Water                                                                                                        9

2.5.2Cement                                                                                                     9

2.5.3 Fine Aggregate                                                                                         10

CHAPTER THREE: METHODOLOGY 

3.0 Research Methodology                                                                                11

3.1 Slump test                                                                                                 11

3.2 Density test                     12

3.3 Compressive strength Test                                                                          13

3.4 Aggregate Impact Value Test                                                                      13

3.5 Sieve Analysis                                                                                              14

3.6 Water Absorption                                                                                         14

3.6 Materials Used                                                                                             14

CHAPTER FOUR: RESULTS AND DISCUSSION

4.0 Results and Disucussion        15

4.1Aggregate Impact Value and Aggregate Crushing Value                            15

4.2 Sieve Analysis of Fine Aggregate                                                                 17

4.2.1 Sieve Analysis                                                                                          19

4.3 Sieve Analysis of coarse Aggregate                                                               21

4.4 Compressive strength of Natural Aggregate (Granite)                                    23     

4.5 Water Absorption Rate                                                                                 29     

CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS 

5.0     Conclusion                        30

5.1     Recommendation                        30

Reference