Pozzolanic properties of rice hush ash (RHA). From Enyong creek catchment had Amorphous silica content of 94% comparable to 93% in Portland cement. Deferent mix ratios of cement-RHA (CEM-RHA) mixtures show toss of compressive strength with increasing percentage of RHA, but the mix ratio of 83.4:16.6 at 28-day curing gave the highest strength of 16.4 Nmm–2. While addition of aggregates improved CEM-RHA compressive strength, it did not necessarily reduce the seepage rate for a mixture having 50% RHA or lower composition. The 50%’RHA or thinner mix ratio in CEM-RHA mixture had water absorption rate of 5.0 cm/day comparable to the value for cement paste and was within the 8 cm/day recommended by ASTM. 33% RHA or thinner RHA in CEM-RHA mixture produced strength and seepage rate comparable to cast cement paste, and is recommended as substitute material for cheaper construction purposes; also its utilization holds good prospects for eco-friendly wetland environment. Further improvement on fineness better than 45um grade and an optimum mix raios with sand to improve strength development for the cheap substitute building material is recommended.
