Characterization of sugarcane bagasse ash (SBA) and its evaluation for use in alkali-activated slag mixtures

Abstract

This work proposed to incorporate the sugarcane bagasse ash (SBA) with a high content of organic matter (loss on ignition of 35.87%) in alkali-activated mixtures with blast furnace slag. After grinding SBA, replacement ratios of 10%, 20%, and 30% of the ground ash were used for the flowability evaluation. The mixtures containing 20% and 30% showed a dry consistency, then only the mixture with 10% of slag was used for the other tests. The use of an air-entraining admixture led to an improvement in the flowability of the alkali-activated mixtures. X-ray diffraction results showed that both SBA and the air-entraining admixture did not interfere in the mineralogical composition of the hydrated products. However, the use of SBA led to a decrease in the compressive strength of about 20% to 28%. In conclusion, SBA proved to be viable for use in alkali-activated mixtures considering its effect on mechanical performance.

Keywords:
sugarcane bagasse ash; blast furnace slag; alkaline activation