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.