Comparative Studies On The Partial Replacement of Cement With Selected Ashes In Concrete Production Using Bida Natural Stones

Abstract

Abstract

In this research two different ashes were separately used as partial replacement for cement in concrete production. They include 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, Aggregate Impact Value (AIV) and Aggregate Crushing Value (ACV) were carried out on the aggregates. Workability test was carried out on fresh concrete containing the two ashes RHA and BPA to ascertain the compressive strength of concrete containing ashes as partial replacement for cement. 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%. Compressive strength test was carried out on concrete at 7, 14, 21 and 28days. 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.