Coconut Shell Ash As Partial Replacement of Ordinary Portland Cement In Concrete Production

Abstract - The cost of cement used in concrete works is on the increase and unaffordable yet the need for housing and other constructions requiring this material keeps growing with increasing population thus the need to find alternative binding materials that can be used solely or in partial replacement of cement. Agricultural waste material in this case coconut shells which is an environmental pollutant are collected and burnt in the open air uncontrolled combustion for three hours to produce coconut shell ash CSA which in turn was used as pozzolana in partial replacement of cement in concrete production. Concrete cubes were produced using various replacement levels of 0 10 15 20 25 and 30 percent of OPC with CSA. A total of 54 cubes were produced and cured by immersing them in water for 7 14 and 28 days respectively. Properties such as compressive strength density setting times and pozzolanic activity index were determined. The results showed that the densities of concrete cubes for 10 -15 replacement was above 2400Kgm3 and the compressive strength increased from 12.45Nmm2 at 7days to 31.78Nmm2 at 28 days curing thus meeting the requirement for use in both heavy weight and light weight concreting. Thus 10 -15 replacement of OPC with CSA is recommended for both heavy weight and light weight concrete production.