Extraction of Silica from Sugarcane Bagasse Ash for Cement Replacement in Concrete: Effect of Treatment and Burning Temperature

Abstract

Increasing amounts of agricultural and industrial wastes have prompted researchers to re‑use the wastes as prospective cement replacement materials. Sugarcane bagasse is an agricultural waste that is widely available as a by-product of sugar and ethanol industries. As sugarcane bagasse possesses a high pozzolanic reactivity owing to its high silica content, the potential of extracting silica from sugarcane bagasse ash (SCBA) for cement replacement has to be explored. In the present study, analytical and compressive strength tests were performed on concrete samples to determine the effect of replacing cement with silica extracted from SCBA. Influences of treatment and burning temperature for conversion of sugarcane bagasse to SCBA on the analytical and compressive strength test results were also investigated. Raw and treated bagasse were burned in a muffle furnace for one hour at 600, 700 and 800°C to produce untreated and treated SCBA, respectively. Hydrothermal synthesis was performed on the SCBA for extraction of silica gel. Three types of concrete samples were prepared, which are the control sample that does not contain any cement replacement material and samples that contain 5% silica from untreated and treated SCBA. Compressive strength tests were performed on the samples after seven days of curing. Findings indicate that treatment of the bagasse was essential to produce SCBA of adequate silica content that can improve the compressive strength of the concrete. The increase in compressive strength is at its highest at the burning temperature of 700°C, where a change of +8.05% was achieved.