Evaluating Finely Ground Coal Bottom Ash for Property Self-Compacting Concrete

Abstract

This study investigates the feasibility of utilizing finely ground coal bottom ash (FGCBA) as a supplementary cementitious material in self-compacting concrete (SCC), with an emphasis on its technical performance and environmental implications. Cement was partially replaced by FGCBA and fly ash (FA) at 20%, 40% and 60% substitution rates under water-to-binder (W/B) ratios of 0.4, 0.45 and 0.5. A comprehensive evaluation of the properties of fresh and hardened concrete—including slump flow, setting time, compressive strength, air content, chloride ion permeability and water absorption—was conducted. The results indicate that FA improves workability and enhances long-term strength development, while FGCBA—despite its lower early-age strength—significantly improves durability, particularly in terms of chloride resistance and microstructural densification. These findings underscore the potential of FGCBA as a viable low-carbon alternative in cementitious systems, contributing to resource efficiency and the achievement of circular economy objectives in the construction sector.