The Use of Coconut Fibre Ash as a Partial Replacement for Cement

Abstract

The cost of cement used in the concrete works is on the increase and unaffordable particularly in the rural areas, yet the need for housing and other construction especially sanitation facilities requiring this material keeps growing as population figure keeps increasing. Thus the need to find alternative binding materials that can be used solely or in partial replacement of cement for construction of sanitation facilities. Agricultural waste material, in this case, Coconut Fibre Ash (CFA), which is an environmental pollutant, are collected dried and burnt into ash. Coconut Fibre were obtained locally from Isu village of Anambra State. The fibres were properly dried  and  taken to National Geosciences Research Laboratory, Kaduna State where the fibres was burnt at a temperature range of  600°C - 700°C until the fibres turned into ash.The initial time before firing the ash was 12 noon and the final time was 1:40 pm. The model of the industrial oven is Kohaszati Gyarepito Vallalat Bupapest. The ash was then allowed to be cool and collected and made to pass through 150 micron sieve. Sample of the ash was taken to determine the chemical composition of the coconut fibre ash, which in turn was used as a pozzolana in partial replacement of cement in concrete production. Concrete cubes were produced using various replacement levels of 0, 10, 30, 50, 70 and 90 percent of ordinary Portland cement (OPC) with CFA. A total of 50 cubes were produced and cured by immersing them in water for 7, 14, 28, 42, 63 & 90 days respectively. Properties such as compressive strength, slump test of cubes and flexural strength of beams were determined. The result showed that the compressive strength of cubes of 10 - 30% replacement increased from 9.23 N/mm2 at 7 days curing to 90 days curing at 22.05 N/mm2, meeting the requirement for heavy and light weight concreting. Also 10% replacement of OPC with CFA is recommended for concrete beam production.