The growing interest in industrial byproducts stems from their potential to improve the strength and durability of construction materials. This study evaluates the effects of cement and ultrafine ground-granulated blast furnace slag treatment of coal bottom ash by incorporating binder dosages of 6 %, 7 %, and 8 % and examining the mechanical and microstructural characteristics after curing for 7, 14, and 28 days. The test results showed a progressive increase in the unconfined compressive strength of coal bottom ash with the binder dosage and curing period. The optimum binder dosage for both binders was determined as 8 %, at which the ultrafine slag-treated coal bottom ash achieved a 26 % higher strength than that of the cement-treated coal bottom ash. Durability evaluation showed that the cement-treated samples withstood up to four wetting-drying cycles, whereas the ultrafine slag-treated samples maintained their integrity for three cycles. Microstructural analysis confirmed enhanced pozzolanic reactions in both binders, leading to the formation of ettringite and other hydration compounds, despite the high sulfate content of the ash. These findings demonstrate the potential of cementitious binder-treated coal bottom ash as a sustainable material for geotechnical and construction applications, contributing to effective waste utilization and environmental conservation.