A Research on the feasibility of using landfill fly ash as a Portland cement substitute

When fly ash is disposed of without being used for any purpose, fly ash landfills are an issue for all power stations. This study investigates the possibility of substituting Portland cement type I with fly ashes that have a 6–24 month disposal period from power plant landfills in India. The fly ashes that were disposed of were pulverized to lower their median particle sizes from 55.4 to 99.3 µm to roughly 7.1 to 8.4 µm. The physical and chemical characteristics of both the original and ground-disposed fly ashes were examined. Compressive strengths of the resulting mortars were measured when Portland cement type I and discarded fly ash made up 10%, 20%, and 30% of the cementitious material, respectively. The results demonstrated that most of the initial fly ash particles were solid and spherical with some irregular shape, but the particles of fly ash that had been ground up were solid and irregularly shaped. There was significant fluctuation in the CaO and LOI concentrations of fly ashes that were disposed of at varying disposal times. Initial fly ash mortar compressive strengths were low; however, over seven days, the ground fly ash mortars' strengths exceeded 75% of the conventional mortar and reached 100% after sixty days. Despite being exposed to the elements for 24 months, based on the findings, ground-disposed fly ashes could be utilized as a partial cement substitute in concrete due to their high pozzolanic properties.