ABSTRACT
Sand has traditionally been used as fine aggregate in structural concrete. It is usually imported from relatively distant places at high costs, and this increases the overall cost of making concrete and of providing housing in various Nigerian communities. This study investigates the performance of 409/o of laterite as fine aggregate in place of sand, and specifically seeks to determine whether lateritic concrete containing pies would satisfy the minimum compressive strength requirement of BS 8110 (1997) for use in reinforced concrete works, which is 25 N/mm. Ordinary Portland Cement was used as binder. 40%Laterite was used as fine aggregate, while granite was replace by pks which varied from 0% to 50% at intervals of l 0%.The mix design used for the concrete mix is 1:2:4 and the water /cement ratio used is0.5m.The compaction factor test was used to~ the workability of the fresh concrete .The compressive strengths and densities of cured concrete cubes of sizes, 150mmx}50mmxJ50mm were evaluated at 7days, 14days, 2ldays, 28days,60days and 90days curing day in total taking the number of cubes to 126cubes . Increase in the percentage replacement of granite lowered compressive strength and workability. The result shows that control bad 10mm and 0% pks had 6mm.tbis reduction in slump is as a result of the 40% replacement of sand aggregate with laterite aggregate. The mix containing 1 O"/o pks had slump of Omm(zero).This is the result of the replacement of granite aggregate with pks aggregate, which have a high water absorption rate. At 50% content shear slump took place and the test was repeated again, shear slump occurred. It was also observed that the compressive strength of concrete increased rapidly with age until the 28th day after which strength developed or reduced gradually until the 90th day. The control concrete had the greatest compressive strength at all the curing ages ,the compressive strength of concrete at 28 days were in range of 8.71N/mm2 to 24 N/mm2 and those of7 days varied from 4.65 N/mm2 to 15.99 N/mm2• Compressive strength values of the normal weight concrete is about twice that of the palm kernel shell which is normal as PKS is lighter and workability is also reduce. Therefore it can be used to produce lightweight concrete like lintel and roads.
