Experimental investigation on properties of concrete mortar incorporating spent bleaching earth waste as supplementary cementitious material

Abstract

This study presents the experimental investigation on properties of concrete mortar incorporating spent bleaching earth waste. Spent bleaching earth (SBE) is a solid waste from the palm oil refinery industry and is commonly used to remove coloring, metals, dirt, and other unwanted components in the oil. In this study, the purpose of using SBE material in the concrete mortar was as a partial replacement of cement. As natural SBE waste has relatively high oil content, a pre-processing treatment of natural SBE is needed to reduce the oil content of the spent bleaching earth. The pre-processing treatment of SBE was performed by extracting the oil content using acetone liquid. After extracting the oil content, the solid SBE was then used to supplement the cement content in the mortar. The mix design used in the test was based on the ASTM C311. The SBE content used in this research varied from 5% to 20%. The result indicates that the pre-processing treatment can reduce the oil content of the SBE and result in better compressive stress compared to the mortar with non-pre-processing treatment. Furthermore, the addition of 5% SBE as supplementary cementitious materials can enhance the compressive stress of the mortar compared to the normal concrete without SBE.