TABLE OF CONTENTS
CERTIFICATION i
DEDICATION ii
ACKNOWLEDGEMENT iii
LIST OF TABLES vii
LIST OF FIGURES ix
ABSTRACT xi
CHAPTER ONE 1
INTRODUCTION 1
1.1 Background of the study 1
1.2 Scope 4
1.4 Justification 5
1.5 Statement of Problem 5
1.6 Aim 5
1.7 Objectives 5
CHAPTER TWO 6
LITERATURE REVIEW 6
2.1 Properties of concrete with POFA 6
2.1.1 Physical properties 6
2.1.2 Chemical Properties of POFA 7
2.1.3 Mechanical properties of POFA 8
2.2 Compressive Strength of Concrete with Replaced POFA 10
2.3 Ultrasonic Pulse Velocity (UPV) of Concrete with Replaced POFA 13
2.4 Workability of Concrete with Replaced POFA 14
2.5 Porosity of Concrete with Replaced POFA 16
2.6 Permeability of Concrete with Replaced POFA 18
2.7 Properties of Cement 19
2.7.1 Physical properties of Cement 19
2.7.2 Mechanical properties of Cement 20
2.7.3 Chemical Properties of Cement 20
2.7.4 Cement hydration 20
CHAPTER THREE 22
Study Area 22
3.0 Materials Used and Methodology 22
3.1. Materials 22
3.1.1 Cement 23
3.1.2 Aggregate 23
3.1.3 Granite 23
3.1.4 Gravel 23
3.1.5 Water 24
3.1.6 Palm Oil Fuel Ash (POFA) 24
3.2 Methodology 25
3.2.1. Sieve Analysis Procedure 25
3.2.2 Specific Gravity of Ordinary Portland Cement Determination 26
3.2.2.1 Experimental Procedure 27
3.3: Concrete Mix Design 29
3.4 Fresh Concrete Workability 30
3.5 Density 31
3.6 Determination of Compressive Strength 31
CHAPTER FOUR 33
RESULTS AND DISCUSSIONS 33
4.1 Oxides Composition of POFA 33
4.2 Grain size distributions from sieve analysis 34
4.3 Compressive Strength Test Results 35
4.4 Optimum Mix Ratio Determination 52
CHAPTER FIVE 53
CONCLUSION AND RECOMMENDATIONS 53
5.1 Conclusion 53
5.2 Recommendation 54
REFERENCES 55
LIST OF TABLES
Table2. 1: Chemical composition range of OPC and POFA 7
Table2. 2: Chemical composition analysis in POFA 8
Table 2. 3: Compressive strength of concrete with various percentages of POFA 10
Table 2. 4: Tensile strength of concrete by the addition of various % of POFA 10
Table 3. 1: Concrete mix design based on design expert 2
Table 4. 1: Oxides composition of POFA 33
Table 4. 2: Fine sand grain size distributions from sieve analysis 34
Table 4. 3: Granite size distributions from sieve analysis 35
Table 4. 4: specific gravity of cement and POFA 35
Table 4. 5: Compressive strength at 7 days of curing age 36
Table 4. 6: Compressive strength for 28 days curing age 40
Table 4. 7: Compressive strength for 56 days curing age 44
Table 4. 8: Compressive strength for 90 days curing age 46
Table 4. 9 summary of compressive strength (n/mm2) at different POFAmix ratio 49
Table 4. 10: Regression analysis for 7 days age concrete 50
Table 4. 11: Regression analysis for 28 days age concrete 50
Table 4. 12: Regression analysis for 56 days age concrete 51
Table 4. 13: Regression analysis for 90 days age concrete 51
Table 4. 14: Analysis of variance for compressive strength 51
LIST OF FIGURES
Figure 2. 1: Strength versus UPV 9
Figure 2. 2: Compressive strength versus POFA replacement percentage 12
Figure 2. 3: Strength activity index of POFA mortar 13
Figure 2. 4: Relationship between UPV and replacement percentage 14
Figure 2. 5: Slump flow against POFA percentage 16
Figure 2. 6: Relationship between porosity and POFA content 17
Figure 2. 7: Relationship between strength and porosity of 80% content of POFA mortar 18
Figure 2. 8: relationship between permeability and replacement level of POFA 19
Figure 3. 1: Map of Maiduguri town showing Ramat Polytechnic 22
Figure 3. 2: Granite 23
Figure 3. 3 Palm oil kernel and ash 25
Figure 3. 4: sieve arrangement 26
Figure 3. 5: POFA replacement percentage (25% – 35%) 29
Figure 3. 6: Granite replacement percentage (0% – 100%) 29
Figure 3. 7: Cubes cast and curing 30
Figure 3. 8: Compressive strength test- 32
Figure 4. 1: Graph for grain size distribution for fine sand 34
Figure 4. 2: Graph for grain size distribution for granite 35
Figure 4. 3: Compressive strength vs granite and POFA at 7 days curing age 37
Figure 4. 4: Slump height vs granite and POFA at 7 days curing age 38
Figure 4. 5: Predicted and actual compressive strength at 7 days curing age 39
Figure 4. 6: Predicted and actual slump height at 7 days curing age 39
Figure 4. 7: Compressive strength vs granite and POFA at 28 days curing age 41
Figure 4. 8: Sump height vs granite and POFA at 28 days curing age 42
Figure 4. 9: Predicted and actual compressive strength at 28 days curing age 43
Figure 4. 10: Predicted and actual slump height at 28 days curing age 44
Figure 4. 11: Compressive strength vs granite and POFA at 56 days curing age 45
Figure 4. 12: Slump height vs granite and POFA at 56 days curing age 46
Figure 4. 13: Compressive strength vs granite and POFA at 90 days curing age 47
Figure 4. 14: Slump height vs granite and POFA at 90 days curing age 48
Figure 4. 15: Predicted and actual compressive strength at 28 days curing age 48
Figure 4. 16: Predicted and actual slump height at 28 days curing age 49
ABSTRACT
Utilizing Palm Oil
Fuel Ash (POFA) in concrete mix is a major way of turning waste to wealth.
Gravel as an aggregate is cheaper than granite. Thus, obtaining an optimum
combination of these materials in achieving a maximum compressive strength in
concrete will go a long way in helping the construction industry.The study was carried out to establish an
optimum replacement ratio for Palm Oil Fuel Ash (POFA) blended granite-gravel
of concrete. Uniform water/binder (w/b) ratio of 0.5 and mixes ratio of 1:2:4
was utilized. Thirteen runs of experiments plus control were designed using the
Central Composite Response Surface method (Design Expert). Based on the
analysis, the increase in granite
volume led to increase in compressive strength. However, increase in POFA
percentage led to decrease in compressive strength at 7, 28, 56 and 90 days
curing ages. The study also observed highest compressive strength at 25%
POFA replacement and lowest at 35% replacement. Also, for granite, highest and
lowest compressive strength were achieved at 100% and 0% replacement
respectively. However, for slump height, the higher the percentage of granite
or POFA in concrete, the higher the slump height. The optimization analysis
showed that, at 29.69% POFA and 98.75% Granite, compressive strength of 24.29
N/mm2 and slump height of 89.36mm were achieved. The optimum
strength found is slightly higher than the maximum strength achieved (24.27N/mm2)
at 90 days and also, slightly lower than the control (25.33 N/mm2).
CHAPTER ONE
INTRODUCTION
1.1 Background of the study
Concrete is regarded as the primary and widely used construction ingredient around the world in which cement is the key material. However, large scale cement production contributes greenhouse gases both directly through the production of CO2 during manufacturing and also through the consumption of energy (combustion of fossil fuels). Moved by the economic and ecological concerns of cement, researchers have focused on finding a substitution of cement over the last several years. In order to address both the concerns simultaneously many attempts have been made in the past to use materials available as by product or waste. This is due to the fact that the use of by product not only eliminates the additional production cost, but also results in safety to the environment. Hence, the development and use of blended cement is growing rapidly in the construction industry mainly due to considerations of cost saving, energy saving, environmental protection and conservation of resources. A number of investigations have been carried out with Palm oil fuel ash (POFA), an agro-waste ash, as potential replacement of cement in concrete. Sata et al. (2004) found compressive strength of 81.3, 85.9, and 79.8 MPa at the age of 28 days by using improved POFA with a reduced particle size of about 10 microns in concrete as replacement of 10%, 20% and 30% of cement respectively. They also reported highest strength at 20% replacement level. Tangchirapat [2009] observed the compressive strengths of ground POFA concrete in the range of 59.5–64.3 MPa at 28 days of water curing and with 20% replacement it was as high as 70 MPa at the end of 90 days of water curing. However, the drying shrinkage and water permeability were noted to be lower than that of control concrete with improved sulphate resistance. Past researchers also depict that both ground and un-ground POFA increase the water demand and thus decrease the workability of concrete. However, ground POFA has shown a good potential for improving the hardened properties and durability of concrete due to its satisfactory micro-filling ability and pozzolanic activity.
