SUSTAINABLE PRODUCTION OF SANDCRETE HOLLOW BLOCKS FROM VARYING MIXTURES OF THREE LOCALLY SOURCED MATERIALS

Abstract

Sandcrete blocks remain the most utilized walling unit in the development of physical infrastructure in developing countries like Nigeria. However, inflation among other factors have influenced the cost of building materials, thus making housing unaffordable for common people. There is need for indigenous materials that are cheaper to be used as partial replacement in the production of sandcrete blocks with the desired properties at low cost. This will drastically reduce the cost of production and construction. This study therefore aims at producing sandcrete hollow blocks using Igbokoda sand and lateritic soil as partial replacement of stone dust at varying percentages. Preliminary tests such as sieve analysis, specific gravity, moisture content and bulk density of the aggregates were carried out to assess their suitability. Thereafter, different percentage by mixed proportion of 0%, 10%, 20%, 30%, and 40% of these aggregates with cement and water of sandcrete blocks produced at all levels of replacement were examined for water absorption capacity, compressive strength and split tensile strength. The result shows that the aggregates used were suitable for the experimental work. In addition, the percentage of water absorption ranges from 1.89% to 4.29% for the 21 and 28 days curing period considered. The average percentage water absorption for both curing days is 2.64 ± 0.26 and 2.93± 0.17 respectively with day 28 having the highest absorption rate. The sandcrete block mixture containing only stone dust and lateritic soil at replacement level 90:10 gives the best compressive strength values of 2.8 N/mm2 while mixture containing only stone dust gives the best outcome for the split test strength. In overall, the results obtained for various mixes satisfy the requirements of the Nigerian Industrial Standard (NIS) (NIS: 2004). Therefore, partial replacement of stone dust with other cheap aggregates such as Igbokoda sand and lateritic soil is a viable option for economic and sustainable building construction.