Effect of Rice Husk Ash (RHA) and Slag as Partial Replacement of Cement on Reinforced Concrete Slabs

Abstract

The increasing demand and consumption of cement have necessitated the use of slag, fly ash, rice husk ash (RHA), and so forth as a supplement of cement in concrete construction. The aim of the study is to develop a replacement of the cement with rice husk ash and slag combined with chemical activator. NaOH, Ca(OH)2, and KOH were used in varying weights and molar concentrations. Partial replacement of cement was tested for its consistency, setting time, flow, compressive strength, and fire. The consistency and setting time of the Partial Z-Cement (Zero cement) paste increase with increasing RHA content. The replacement of cement mortar achieves a compressive strength of 22–25MPa at  28 days with 5% NaOH or at 2.5or non used activator molar concentrations. The tested slabs were made of concrete and reinforced with bars with 10 mm diameter having and compressive strength evaluated from the compressive tests. The analysis of the slab deflection behavior has been presented after fire of samples. The results show the different character of the load-deflection relationship of a replacement of the cement with rice husk ash and slag reinforced slabs compared to traditionally reinforced slabs.