Effect of Curing Methods and Time on the Strength of Silicate Concrete made from Corn Cob Ash

Corn cob, an agricultural waste material was converted to ash and used as a pozzolanic material in the partial replacement of cement in concrete. This is expected to reduce cost and promote green and sustainable environment. However, this research report presents the effect of curing methods and curing time in the strength of the silicate concrete so produced. M25 concrete with water/cement ratio of 0.45 was prepared with corn cob ash (CCA) replacements of 0, 10, 20 and 30%. They were cured for 14, 28, 42 and 56 days using different curing methods. Though the compressive strength improved over time, it however declined with increase of CCA content. The ponding method of curing gave the highest compressive strengths of 34.6N/mm 2 and 27.7N/mm 2 at 0% and 10% CCA replacements respectively While the spraying method produced the list strength. The CCA did not improve the compressive strength up to 56 days but may probably do beyond the date due to the slow hydration of pozzolanas.