ABSTRACT
This research aimed at empirical investigation of flexural strength of compressed stabilized earth slab. Two sets of 500 x 500 x 150mm compressed stabilized earth slabs were cast. One set was cast with BRC mesh of 5 x 150 x 150mm with strength of 250N/mm2 as reinforcement and the other set was cast without reinforcement. Eight mixture proportions of laterite, river sand and cement were used in this research work and optimum moisture content obtained from compaction test of the mixture proportions were used for the casting of the compressed stabilized earth slabs and compressed stabilized earth cubes. Each mixture proportion was used to cast twelve compressed stabilized slabs and six compressed stabilized earth cubes. A total of ninety six compressed stabilized earth slabs and forty eight compressed stabilized earth cubes of 150 x150 x150mm were cast. Comprising 48 reinforced compressed stabilized earth slabs and 48 unreinforced compressed stabilized earth slabs, out of which, 24 of reinforced compressed earth slab and 24 unreinforced compressed earth slab were compressed using 6N/mm2 compaction load while the remaining equal number of 24 reinforced and unreinforced were respectively compressed with 8N/mm2 compaction load, using Magnus frame. The maximum flexural strength, central deflection and moment obtained using 6N/mm2 compaction load on reinforced compressed stabilized earth slab were 4.74x10-4N/mm2, 3.17x10-3mm and 887.97Nmm while the corresponding value for unreinforced compressed stabilized earth slab were 4.06x10-4N/mm2, 2.71x10-3mm and 760.56Nmm. Also, the maximum flexural strength, central deflection and moment obtained using 8N/mm2 compaction load on reinforced compressed stabilized earth slab were 5.50-4N/mm2, 3.68x10-3mm and 1030.8Nmm while the corresponding value for unreinforced compressed stabilized earth slab were 4.53x10- 4N/mm2,3.03x10-3mm and 849.36Nmm. From this research, it can be concluded that reinforced compressed stabilized earth slabs with high compaction load have high flexural strength, central deflection and moment when compare with unreinforced compressed stabilized earth slabs.
Keywords: compressed stabilized earth slab, flexural strength, compressive strength, laterite, river sand.
TABLE OF CONTENT
Certification Dedication Acknowledgement Abstract
Table of contents
List of Tables
List of Figures
List of Plates
Definition of Notations
CHAPTER ONE: INTRODUCTION
1.1Background of Study
1.2 Statement Problem
1.3 Objective of study
1.4 Justification
1.5 Scope of study
CHAPTER TWO: LITERATURE REVIEW
2.1 History of Earthen Construction
2.2 Compressed Stabilized Earth Block Technology (CSEB)
2.3 Principles of Stabilization
2.3.1Cement Stabilization
2.3.2 Lime Stabilization
2.3.3 Pozzolanas
2.3.4 Blast Furnace Slags
2.3.5 Fly–Ash
2.4 Fiber Reinforcement in Compressed Stabilized Earth Blocks
2.5 Practical Applications of CSEB as a Building Material
2.6 Compressive Strength of CSEB
2.7 Constituents of Reinforced Compressed Stabilized Earth Slabs
2.7.1 Cement
2.7.2 River sand
2.7.3 Laterite
2.7.4 Clay
2.7.5 Silts
2.7.6 Water
2.7.7 Reinforcement
2.8 Magnus Frame
2.9 review of previous works related to compressed stabilized earth slab
CHAPTER THREE: MATERIALS AND METHOD
3.1 Materials
3.1.1 Cement
3.1.2 River Sand
3.1.3 Laterite
3.1.4 Water
3.1.5 BRC Mesh
3.1.6 Clay
3.2 Method
3.2.1Sieve Analysis
3.2.2 Moisture Content Test
3.2.3 Compaction Test
3.2.4 BRC Mesh Preparation
3.2.5 Method of Batching and Mixing
3.2.6 Mixing of Materials
3.2.7 Casting of Compressed Stabilized Earth Slab and cubes 3.2.8 Curing Condition
3.2.9 Crushing Of Compressed Stabilized Earth Cubes and Slabs
3.3 Calculation of Maximum Central Deflection and Moment of Slab using Finite Difference Method
CHAPTER FOUR: RESULTS AND DISCUSSION
4.1 Results
4.1.1Results Obtained From Compaction Test
4.1.2 Loading Compressed Stabilized Earth Slab to Failure at 28 Day Strength
4.1.3 Representation of Graphs
4.2 Discussions
4.2.1 Discussions of Materials Results
4.2.2 Discussion of Graph Results
4.2.2.1Fines and Sand versus Flexural strength
4.2.2.2 Compressive strength versus Flexural strength 4.2.2.3 Fines and Sand versus Compressive strength
CHAPTER FIVE: CONCLUSION AND RECOMMENDATION
5.1 Conclusions
5.2 Recommendations
5.3 Contributions to Knowledge
References
Appendices
LIST OF TABLES
Table 2.1: The properties of the block (CSEB)
Table 2.2: Types of stabilizers for different soil types
Table 3.1: Percentage mixture proportion and the optimum moisture content Table 4.1: compressed stabilized earth cubes strength at 28days strength
Table 4.2: Crushing loads of compressed stabilized earth slab for compaction load of 6N/mm2
Table 4.3: Crushing loads of compressed stabilized earth slab for compaction load of 8N/mm2
Table 4.4: Central deflection, moment, and flexural strength of reinforced compressed stabilized earth slab and cube strength for compaction load of 6N/mm2
Table 4.5: Central deflection, moment, and flexural strength of unreinforced compressed stabilized earth slab and cube strength for compaction
load of 6N/mm2
Table 4.6: Central deflection, moment, and flexural strength of reinforced compressed stabilized earth slab and cube strength for compaction load of 8N/mm2 61
Table 4.7: Central deflection, moment, and flexural strength of reinforced compressed stabilized earth slab and cube strength for compaction
of 8N/mm2
Table A1: Moisture content of river sand and laterite soil.
Table B1: Percentage of fines and sand in view in laterite soil Table B2: Composition of fines and sand in laterite, fines in view,
total sand and river sand
Table B3. Mixture proportions of laterite, river sand and cement Table C1. Moisture content, average moisture content, density and dry
density of compaction test
TableD1 shows the result of the sieve analysis of river sand Table D2 shows the result of the sieve analysis of laterite soil
LIST OF FIGURES
Figure 3.1: Square plate divided into four panels 51
Figure 4.1: Percentage fines versus flexural strength using compaction load of 6N/mm2 62
Figure 4.2: Percentage sand versus flexural strength using compaction load of 6N/mm2
63
64
Figure 4.3: Cube strength versus flexural strength load of 6N/mm2
using compaction
Figure 4.4 Percentage Fines versus Cube strength using compaction load of 6N/mm2 65
Figure 4.5: Percentage sand versus cube strength using compaction load of 6N/mm2
Figure 4.6: Percentage fines versus flexural strength using compaction load of 8N/mm2
Figure 4.7: Percentage sand versus flexural strength using compaction load of 8N/mm2
Figure 4.8: Cube strength versus flexural strength using compaction load of 8N/mm2 69
Figure4.9: Percentage fines versus cube strength usingcompaction load of 8N/mm2
Figure 4.10: Percentage sand versus cube strength using compaction load of 8N/mm2
Figure C1: Average moisture content versus dry density for 12.6% fines
FigureC2: Average moisture content versus dry density for 13.9% fines
Figure C3: Average moisture content versus dry density for 15.2% fines
Figure C4: Average moisture content versus dry density for 16.5% fines
Figure C5: Average moisture content versus dry density for 17.8% fines
Figure C6: Average moisture content versus dry density for 19.1% fines
Figure C7: Average moisture content versus dry density for 20.4% fines
Figure C8: Average moisture content versus dry density for 21.7% fines
Figure D1: Gradation curve of river sand
LIST OF PLATES
Plate G1: Frontal view of Magnus frame
PlateG2: Compressing of earth slab in Magnus frame
Plate G3: Compressed stabilized earth slab
Plate G4: Compressed stabilized earth slabs ready for crushing after curing
Plate G5: Crushing of compressed stabilized earth slab in Magnus frame
Plate G6: Crushing of compressed stabilized earth cubes
Figure D2: Gradation curve of laterite
Pius, A (2021). Empirical Investigation of the Flexural Strength of Compressed Stabilized Earth Slab. Afribary. Retrieved from https://afribary.com/works/empirical-investigation-of-the-flexural-strength-of-compressed-stabilized-earth-slab
Pius, Anyadiegwu "Empirical Investigation of the Flexural Strength of Compressed Stabilized Earth Slab" Afribary. Afribary, 21 Feb. 2021, https://afribary.com/works/empirical-investigation-of-the-flexural-strength-of-compressed-stabilized-earth-slab. Accessed 25 Apr. 2024.
Pius, Anyadiegwu . "Empirical Investigation of the Flexural Strength of Compressed Stabilized Earth Slab". Afribary, Afribary, 21 Feb. 2021. Web. 25 Apr. 2024. < https://afribary.com/works/empirical-investigation-of-the-flexural-strength-of-compressed-stabilized-earth-slab >.
Pius, Anyadiegwu . "Empirical Investigation of the Flexural Strength of Compressed Stabilized Earth Slab" Afribary (2021). Accessed April 25, 2024. https://afribary.com/works/empirical-investigation-of-the-flexural-strength-of-compressed-stabilized-earth-slab