ASSESSMENT OF CALCIUM CARBIDE WASTE AND BAMBOO LEAF ASH MIXES AS PARTIAL REPLACEMENT OF CEMENT IN CONCRETE

Abstract

The cost and environmental damage of cement production has led researchers into searching for alternative binders that are friendly and contribute to waste management. This research is set out to investigate the use of this industrial waste, Calcium Carbide Waste Powder (CCWP) and an agricultural waste, Bamboo Leaf Ash (BLA) as partial replacement of cement in concrete. This will be a cheaper alternative to conventional admixtures, which will lead to reduction in the cost of concrete in construction. This will also be a means of addressing the environmental pollution caused by the accumulation of these wastes. Chemical composition analysis on Calcium Carbide Waste Powder (CCWP) and Bamboo Leaf Ash (BLA) confirmed their statuses as non pozzolanic material rich in Calcium oxide (CaO) component and pozzolanic material rich in Silicon oxide (SiO2), respectively. The effect of (BLA), (CCWP) and Binary CCWP/BLA on concrete was investigated for the replacement by addition of 5%, 10%, 15% and 20% respectively by weight of Ordinary Portland Cement (OPC) to concrete. The research produced concrete with (BLA) cement replacement, concrete with (CCWP) cement replacement and concrete with (CCWP/BLA) cement replacement with varying proportions. The slump heights and compaction factors of fresh 1:2:4 concrete mixes with 0.60 water-cement ratio in the order above was determined and a total of one hundred and fifty-six (156) 150mm x 150mm x 150mm cubes of hardened concrete were tested for compressive strength at 7, 21, 28 and 56 days of curing for all specimen types with standard procedure to obtain an optimum mix design. The results obtained from the research shows that the workability properties of the Bamboo Leaf Ash (BLA), Calcium Carbide Waste Powder (CCWP) and Binary Bamboo Leaf Ash/Calcium Carbide Waste Powder cement concrete was found to be better than that with 100% Ordinary Portland Cement (OPC) concrete. Compressive strength test also showed that at optimum replacement levels of 10% (BLA), 10% (CCWP) and 10% binary cement concrete have almost the same strength performance with 100% (OPC) concrete. Twenty-eight (28) and Fifty-six (56) days peak compressive strength values of 13.93 N/mm2 and 16.26N/mm2 respectively was obtained when 10% (CCWP) was mixed with 90% cement (OPC). Values comparable to 28 and 56 days peak compressive strength values of 13.03 N/mm2 and 15.07 N/mm2 are respectively obtained with the use of only cement as binder. The research established (BLA) and (CCWP) as capable of successfully replacing Ordinary Portland Cement (OPC) partially in concrete production either in binary. The research also supports that addition of pozzolanic material (OPC) and non-pozzolanic material (CCWP) to concrete improved the binding property of such concrete which in turn will improve other properties like compressive strength, density, durability etc. The (CCWP) and (BLA) cement have positive effects on the properties of the concrete such as workability, compaction factor, soundness, setting time, density and compressive strength with added advantages in the reduction of cost of concrete, waste problems, and hazard brought about by the production of Ordinary Portland Cement (OPC) in Nigeria.