Pozzolanic Characterization of Rice-Husk-Ash from Two Varieties of Rice in Gombe: A Strategy for Achieving Low Cost Housing

Rice husk ash is a promising pozzolanic material for partial replacement of ordinary Portland cement (OPC) in lightweight concrete construction. With the spate of increasing cost of building materials on daily basis, especially cement, resulting in very high cost of housing, RHA has been found to be an alternative sustainable material that will lead to decrease in cost of mass housing delivery.The objective of the study is to characterize the pozzolanic properties of twoidentified RHA varieties (Jamila and Fadama II) in Gombe, the study area, with a view to determiningthe mechanical properties of lightweight concrete strength at different replacement levels of ordinary Portland cement with the identified RHA varieties. Standard cubes (100mm x 100mm x 100mm) and prisms (100mm x 100m x 500mm) were produced in laboratory. In all204specimens of M15 grade mix were produced, cured in curing tank, and tested by crushing. The strength of the concrete at various replacement of cement viz: 15%, 20%, 25%, and 30% with Rice Husk Ash were compared with controlled mix of same grade M15. The compressive and the flexural strength at 7, 14, 21 and 28 days were determined,and the results at respective days of curing was encouraging. The optimum replacement of rice husk ash with OPC was found to be 20% for Jamila and 30% for Fadama II. The resultscan be used for lightweight construction in low cost housing in the study area