Many s In this study, the effects of variability in the pozzolanic properties of Rice Husk Ash (RHA) gotten from four (4) different locations on the Flexural Properties of Concrete was reported. The different sources where RHA was gotten are; Ogoja, Abakaliki, Adani and Adikpo in Nigeria. It is discovered that the pozolanic properties of RHA varies based on their location. Samples from Ogoja where found to have the highest pozzolanic properties followed by Abakaliki, Adani, and Adikpo, their silica content was found to be 84.55, 76.3, 70.12 and 70.11%respectively. The percentages of RHA used to replace cement in concrete were 5, 10,15,20,25 and 30%.The compressive strength values at 28 day curing period was found to be in the range of 37-42N/mm2 at 5%RHA, 35-39.5N/mm2 at 10%RHA, 30-34.5N/mm2 at 15%RHA, 27-29N/mm2 at 20%RHA, 22-25.6N/mm2 at 25% RHA and 21-24N/mm2 at 30% RHA compared to the controlled sample with a strength value of 42.64N/mm2. Beams of 500x100x100mm were cast and tested for flexural strength. The flexural values ranged from3.15-3.7N/mm2 at 5%RHA, 2.61-3.03 N/mm2 at 10% RHA, 2.16-2.30 N/mm2 at 15% RHA, 1.7-2.0 N/mm2 at 20% RHA, 0.86-1.4 N/mm2 at 25% RHA and 0.62-0.85 N/mm2 at 30% RHA while the results of the controlled sample is 3.84 N/mm2.From the results above it can be deduced that there is a variability in the pozolanic properties of RHA based on location and this has a correlation on their efficacies as a concrete admixture.
