This report studied the comparative analysis of concrete made with two different type of aggregate. The utilization of two different types of coarse aggregate was investigated by testing and comparing their compressive strength. Normal concrete can be produced from different aggregate and it impart different properties to the resulting concrete. The most important property of a concrete is its compressive strength. For the purpose of this work, the two type of coarse aggregate are, local gravel and granite. The fine aggregate is normal sand bought from a local distributor.
Preliminary laboratory investigation was conducted to ascertain the suitability of using the aggregate for construction work. The tests conducted include the sieve test, cement test and slum. Mix ratio of 1:2:4, 1:3:6 and 1:5:7 were adopted for this work and the mix composition was calculated using the absolute weight method. For each type of coarse aggregate, 39cubes of 150mm×150mm were cast to allow the compressive strength to be monitored at 3, 7, 14 and 28 days. The test result shows that concrete proved to have the highest compressive strength with mix ratio 1:2:4 followed by 1:3:6 then 1:5:7. The report also shows that concrete made with granite was stronger with average compressive strength of 27.3 on curing for 28 days compared to gravel 24.1 having cured for the same amount of days. However, the report reveals that it’s not advisable to use mix ratio 1:5:7 for structural elements as it produced a very low compressive strength of 13.7 for granite and 13.2 for gravel.
TABLE OF CONTENTS
Table of content V
List of tables VII
List of figures VIII
- INTRODUCTION 1
1.1 Preambles 1
1.2 Aims and objectives 2
1.3 Scope of study 3
1.4 Purpose ofcomparing compressive strength of concrete 3
2.0 LITERATURE REVIEW 4
2.1 Introduction 4
2.2 Concrete constituent materials 6
2.2.1 Coarse aggregates8
2.2.2 Alternative constituent materials in concrete 9
2.3 Comparison between natural aggregates 10
2.3.1 Shape and surface texture 11
2.3.2 Particle size distribution 12
2.3.3 Aggregate porosity 13
2.3.4 Water absorption 14
2.3.5 Particle density and bulk density 16
2.3.6 Compressive strength 17
2.3.7 Durability 17
3.0 TEST ON MATERIALS AND METHOD 20
3.1 Sieve analysis 20
3.1.1 Apparatus used for sieve analysis 20
3.1.2 Test procedure 21
3.2 Cement test 22
3.2.1 Standard consistency 22
3.2.2 Setting time measurement 23
3.3 Concrete mix 24
3.3.1 Apparatus used for preparation of concrete mix 24
3.3.2 Test procedure for the preparation of concrete mix 25
3.4 Slump test 26
3.4.1 Apparatus used to perform the slump test 27
3.4.2 Test procedure used to perform the slump test 28
3.5 Casting of specimen 28
3.5.1 Precautions taken during the casting of specimen 30
3.5.2 Identification of cubes 30
3.5.3 Demoulding the test cubes 31
3.6 Curing 31
3.6.1 Method of curing specimen 32
3.7 Test on hardened concrete cube 33
3.7.1 Destructive test 33
3.7.2 Compressive strength test 33
4.0 RESULT AND ANALYSIS 35
4.1 Sieve analysis 35
4.1.1 Report of the sieve analysis 36
4.2 Cement test 36
4.2.1 Result of standard consistency of cement 36
4.2.2 Setting time measurement 37
4.3 Quantity of material for concrete cube 37
4.3.1 Estimation for batching 37
4.4 Compressive test result 39
- Graph for comparing the compressive strength of gravel and granite 44
4.4.2 Result and discussion 46
5.0 CONCLUSION AND RECOMMENDATIONS 46
5.1 Conclusion 48
5.2 Recommendations 49
Concrete is the most widely used building material. It is very versatile, has desirable engineering properties, can be molded into any shape, and more importantly is produced with cost effective materials. The knowledge of concrete’s controlled production, maintenance, testing and repair is vital for a discerning designer to ensure its optimal use. In the words of J.W. Kelly, concrete is used to support, to enclose, to surface and to fill. The large number of failure of structures has underlined the need for a better understanding of the behavior of concrete, this in turn warrants the need to have sound knowledge of the selection of materials, mix proportioning, and quality control methods.
However, this project is intended to present the theoretical and practical information in the field of the comparative analysis of the strength of concrete made from local gravel and or granite. It is obligated to help students, professional engineers and those that found pleasure in designing and construction industry. The knowledge helps to gain a broader understanding of aggregate (local gravel and granite) as a construction material for concrete. It also explains the fundamental concept of concrete construction in a simple language and covers the aspect of material science, mix proportioning and construction. It combines sound theory with practical example based on empirical observation from the laboratory experience.
Due to the high cost of different aggregate in the market, the comparative strength of concrete made from different aggregate gives the knowledge of using them in concrete construction. However, the aim of this project is to compare the strength of concrete produced by local gravel and granite to see if there is any way these coarse aggregate can be interchanged during construction especially when there is shortage of any of the material. The knowledge of the comparative strength of different aggregate can help in designing and also reduce the cost of an entire project.
- AIMS AND OBJECTIVES
The aims of the report are as follow:
- To determine the grade of material using sieve analysis and relating various fractions by plotting their graph.
- To perform the cement test
- To prepare a uniform concrete mix.
- To perform the slump test.
- To perform casting of concrete cube 150mm 150mm
- To perform curing of the cubes
- To perform the compressive test.
The objectives of the report are as follow:
- To perform comparison of compressive strength of concrete made with local gravel and that made with granite.
- To perform analysis of the compressive strength/age relation of the concrete.
1.3 SCOPE OF STUDY
The services provided in fulfilling this project include:
- Research study from lecturer and building contractors.
- Online and topic study on compressive strengths of concrete.
- Analysis and planning of activities for the smooth execution of the project.
- Purchasing of the aggregates, cement and other materials.
- Collective effort in preparation and execution of the various tests.
- Formal presentation of the report findings.
1.4 PURPOSE OF COMPARING COMPRESSIVE STRENGTH OFCONCRETE
The primary focus of this report was to document results obtained from laboratory test for the compressive strength of concrete with coarse aggregate of local gravel and granite. The report will create a basis for comparing which of the two coarse aggregate is suitable for which work and if one of them can be interchanged for one another in construction works in case of shortage of material or management of resources without compromising the set standard. The best method to determine the compressive strength of concrete is to perform the compressive test using the compressive machine to crush and record the maximum load and unusual feature in the type of failure that occurs.