Feasibility of Coal Bottom Ash as a Supplementary Binding Material in Cement-Based Composites

Over the course of several decades, coal-fired thermal power plants have consistently generated significant amounts of Coal Combustion Products (CCP), such as Coal Bottom Ash (CBA) and Coal Fly Ash (CFA), as by-products. The open disposal of CCP, especially CBA, has led to serious environmental challenges, including land occupation and contamination risks. Additionally, cement production contributes to high amounts of greenhouse gas emissions which exacerbate global warming. This has led to the focus of the study, i.e., to explore the potential of using CBA as a supplementary binder in cement engineering. While implementing its potential usage as a supplementary binder, it is essential to undertake a practicable pre-treatment process for feasible utilization. The fineness of CBA plays a crucial role in influencing the mechanical properties of cement-based composites. This was aimed at analyzing the feasibility of CBA to be implemented as supplementary binding material from different aspects such as physical and chemical properties, microstructural properties, workability, and mechanical properties, as well as its influence on the hardened properties of cement-based composites. Various literatures have been studied and the findings provide valuable insights into the influence of CBA on the feasibility and performance of CBA-based cement composites, offering guidance for optimizing the incorporation of CBA in cementitious systems.