COMPARATIVE STUDIES ON THE PARTIAL REPLACEMENT OF CEMENT WITH SELECTED ASHES IN CONCRETE PRODUCTION USING BIDA NATURAL STONES

Abstract

ABSTRACT This research work investigated the possibility of utilizing Rice Husk ash and Bone Powder ash blended with cement in the production of concrete having sufficient qualities for construction. Two different ashes were separately used as partial replacement of cement in concrete production which includes rice husk ash (RHA) and Bone Powder ash (BPA). Mix design of 1:2:4 were adopted. The ashes were obtained through open air burning. Sieve analysis, Specific gravitytests, Bulk density, Moisture content, AIV and ACV were carried out on the aggregates. Concrete mix were prepared at 100% OPC as control, three trial mix each of RHA and BPA at cement replacement of 5%, 10%, 15%, 20% and 25%. Workability were carried out on fresh concrete containing the two ashes RHA and BPA to ascertain the consistency of the fresh concrete containing ashes as partial replacement for cement. Crushing test were also conducted on the hardened concrete to determine the compressive strength of the concrete at 7, 14, 21 and 28 days. The result showed that 5% RHA has compressive strength is close to control in concrete at 28days while that of 5% BPA was not too close to the control at the 28days. Also from the results obtained it was observed that the partial replacement of cement by RHA and BPA is advantageous, particularly for areas at which the concrete can utilize such as columns, slab, foundation and beam at 5% replacement.