Utilization of Gasifier Ash as a Partial Cement and Sand Replacement in Cement Mortar

Gasifier ash (GA) is a by-product of the gasification step of the integrated gasification combined cycle (IGCC) method in the coal industry. According to the U.S. Environmental Protection Agency (EPA), gasifier ash has been classified as hazardous waste with large quantities of this waste being produced annually. Due to the hazardous nature of GA, and its negative environmental impacts, there is a need to conduct research on innovative ways of utilizing GA. This paper presents a study conducted on utilizing this waste as an alternative construction material. This research investigates the utilization of GA as a possible replacement of both cement and sand. The study was conducted on mortar cubes by incorporating GA in the mix with varying replacements of cement and sand. The paper shows that GA serving as a replacement of up to 10% of sand in mortar can give comparable - if not higher-compressive strength at 7 days. This finding should provide with a useful way for GA to become a sustainable alternative material in the construction industry.