Characteristics of Combined Rice and Wheat Husk Ashes as a Partial Replacement for Cement in Mortar

Abstract

The potential to recycle and utilize agricultural waste as a building material has been demonstrated in a variety of applications. The goal of this study was to assess the feasibility of partially substituting combined rice and wheat husk ashes (CORWHA) for cement in mortar. The two agricultural waste ashes, rice husk and wheat husk, were evaluated separately before being combined. Both husks were burned separately in an open room to reduce volume before being cremated for 2 hours at a regulated temperature of 600 °C to eliminate carbon and generate reactivity. The chemical and physical properties of the ashes were evaluated after grinding and sieving to determine their cementitious qualities before developing and testing 12 mix proportions of CORWHA and cement for mortar production. The mixing was done at three different percentages of cement replacement: 20, 30, and 40%. According to the findings, the maximum cement replacement yielding 5.98 MPa mortar strength is 30%, with a mixed proportion of 11% wheat husk ash (WHA) and 19% rice husk ash (RHA). It was also found that 95% of RHA is silica and 1.67% is alkaline, while 63% of WHA is silica and 12.16% is alkaline, which is good for preventing porosity and corrosion of reinforcement bars. Doi: 10.28991/CEJ-2022-08-04-04 Full Text: PDF