Bamboo Leaf Ash as a Partial Replacement of Cement in Concrete
Chapter One
AIM AND OBJECTIVES
The aim of this project is to study the compressive strength of concrete with cement partially replaced with bamboo leaf ash and the suitability of the material to be used as a cement substitute
The objectives of the projects are:
- To determine the percentage of BLAsh as a replacement for cement of 5%,10%,15%,20%.
- To replace cement with the known percentage of bamboo leaf ash and cast with it.
- To examine the workability of the fresh BLAsh concrete by slump test.
- To compare the strength of cubes cast at 100% of cement with cubes replaced with the known percentage of bamboo leaf.
- To suggest the use of bamboo leaf ash as alternative supplement to cement so as to reduce cost of construction.
CHAPTER TWO
REVIEW OF LITERATURE
Separately from industrial waste, ashes from agricultural sources like bamboo leaf ash (BLAsh) rice husk,coconut husk, peanut shell or fiber shell etc. have been used for making cement substitutes. Previously, numerous works have been carried out to look into the various aspects of ashes with pozzolanic behavior locally, and in many parts of the world. These materials have already been known as supplementary cementing materials. It is a well-known fact the increase in the fineness of pozzolanic materials would lead to significant increase in strength. The extremely fine particles in concrete acts as lubricant in the concrete mix and permit a reduction in water content. Thereby, increasing strength.
Little research has been carried out to study the bamboo leaf waste as pozzolanic materials Dwieidi(2006) reported the reaction between calcium hydroxide (CH) and bamboo leaf ash for four hours (4hr) of reaction, using the differential scanning calorimeter (DSC) technique.
Ernesto Villar (2010) was represents a characterization and study of the pozzolanic behavior between calcium hydroxide (CH) and bamboo leaf ash (BLAsh) which was also obtained by calcining bamboo lead at 6000c for two hours (2hr) in a laboratory electric furnace. To evaluate the pozzlanic behavior, conductometric method was used which is based on the measurement of the electrical conductivity in a Bash/CH solution with the reaction time.
Felix, et al., (2006) in their research, wood waste, saw dust and wood shaving ash, wood waste ash (WWA) of pretreated timber of 0%,5%,10%,15%,20%,25% and 30% by weight of cement was added as a supplement to a concrete of mix proportion 1:2:4, 0.56 cement: sand : coarse aggregate: water cement ratio, and the strengths and the water absorption of the matrix were evaluated. Also, the metal leach ability of WWA was analyzed. The compressive and the flexural strength of WWA concrete was 12.83N/mm2 to 28.66N/mm2 and 3.65N/mm2 to 5.57N/mm2 respectively, with the lowest values obtained at 30% additive level of Ash. Where compared with the strength of plain concrete control, the compressive and flexural strength of WWA concrete were between 62% and 91% and 61% and 98% respectively of the former.
Singh et al (2000) discussed that ecofriendly composite cements may be obtained by partial replacement of Portland cement with certain low cost materials. They studied the hydration of bamboo leaf ash in blended Portland cement. It was concluded that bamboo leaf Ash is an effective pozzolanic materials. When 20 wt.% of bamboo leaf ash was mixed with PPC the compressive strength values of mortars at 28 days of hydration were found to be quite comparable to those of PPC.
Abdullah, M (2005) has studied the behavior of wood ash and ordinary Portland cement concrete, chemical analysis of wood ash, bulk density, sieve analysis and specific gravity of wood ash and aggregates, consistency, setting time and slump test of the fresh paste were conducted to determine the suitability of the materials for concrete making.
CHAPTER THREE
Materials and Methods
Materials Selection
The materials used for the study of compressive strength of concrete partially replace with bamboo leaf ash are; Coir ash, coarse aggregate, fine aggregate and cement.
Coir ash:
The leaf was obtained mostly behind stream. In this research the bamboo leaf were obtained at Alagbado, Ilorin in a cold area as shown in plate 3.1. The leaf were then air dried for few days and burnt in a local pot at about 3800 and in an open space, uncontrolled burning process in which the leaf turned into ash (black in color) as shown in plate 3.2. The quantity and fineness of BLAsh was improve, by grinding until the median particles sizes were 225 microns as shown in plate 3.3
CHAPTER FOUR
RESULTS AND DISCUSSION
In order to determine the performance of BLAsh as partial replacement of cement in concrete, various tests were carried out on the constituent materials, fresh concrete and the hardened concrete. The results are hereby presented on Table 4.1 to 4.13 and figure 4.3.
The test carried out the cement and BLAsh are 0%, 5%, 10%, 15% and 20%. Slump tests on the fresh concrete were compared. Test was carried out on the hardened concrete British accordance with specified standards.
CHAPTER FIVE
CONCLUSION AND RECOMMENDATION
CONCLUSION
Based on the experimental investigations carried out and results obtained, it is therefore concluded that;
- The suitability of using bamboo leaf ash BLA as supplementary cementatious material has been explored.
- The compressive strength or ability of fresh bamboo leaf ash content measured by the slump test reduces as the bamboo leaf ash content increases. It is therefore noticed, that bamboo leaf ash concrete will be workable but not as cement which is in correspondence to (ASTM C 143 or EN 12350).
- The effect of bamboo leaf ash replacement and curing on the concrete density was investigated. But the result show almost similar. This implies that the bamboo leaf ash has no significant effect on the density of the concrete comparatively.
- The compressive strength of the BLA concrete at the end of 28 days at 9%, 5%, 10% 15% and 20% BLA replacement of cement are relatively close with respect to what the control compressive strength indicated from (compressive strength of concrete classes c14 – c35). This show that the BLA can be used optimally as supplementary cementious material in concrete works.
RECOMMENDATIONS
Based on the investigation carried out and conclusion drawn, it is therefore recommended that, to improve on the research work with more reliable results:
- For an optimum compressive strength of concrete to be obtained, at 5% replacement of cement with bamboo leaf ash is recommended
- Prior to preparing the bamboo leaf ash, more economical and reduced labour means should be adopted.
- In the coming future, recycling of waste materials in a more useful way like this should be encouraged by government and any organization with viable programs and adequate funds to encourage interested researchers to venture into it.
REFERENCES
- Abdullahi, M. (2005); Characteristics of Wood ASH/OPC Concrete, Civil Engineering Department, Federal University of Technology, Minna, Niger State, Nigeria (accessed online).
- Arowolo S.G. (2013); The Study of Compressive Strength on Concrete with Partial Replacement of Cement with Bamboo leaf Ash, Final Year Project, Department of Civil Engineering, University of Ilorin, Ilorin.
- Bloem, B.L. (1959); Preliminary Tests of Effect of Sugar on Strength of Mortar, National Ready Mixed Concrete Association, Washington, D.C., Pp.1-4.
- Mehta PK (1987); “Natural Pozzolanans in Supplementary Cementing Materials for Concrete” Ed. VM Malhortra, CANMET, Canada, Pp. 3-33.
- Ogundipe T.M (2014); “Durability of Bamboo leaf Ash Blended Cement Concrete in Sulphate Environment”, Unpublished M.Sc. thesis in the Department of Civil Engineering, University of Ibadan, Nigeria.
- Oyekan G.L. (2007); Effect of Admixtures o the Compressive Strength of Sandcrete Blocks, University of Lagos, Nigeria.
