Evaluation of High-Performance Mortar Characteristics Utilizing Coal Bottom Ash and Limestone Powder as Sustainable Alternatives to Cement

The surge in cement production and resource consumption significantly contributes to CO₂ emissions, prompting environmentalists to seek sustainable solutions. This research explores the potential of utilizing waste materials as binders or aggregates in mortar and concrete mixtures to address issues related to improper waste disposal. Specifically, it evaluates the feasibility and benefits of using industrial by-products, such as coal bottom ash and limestone powder, as partial replacements for cement. Laboratory experiments assessed various replacement levels 0%, 5%, 10%, 15%, and 20% by mass of cement with these materials. The results indicate that coal bottom ash and limestone powder can effectively serve as supplementary cementitious materials, with optimal replacement levels of 10% for limestone powder and 15% for coal bottom ash. The study concludes that both wastes can be suitable alternatives to cement due to their pozzolanic capability and their significant influence on the properties of cement mortars. The study recommends further exploration of both wastes as sustainable alternatives to reduce greenhouse gas emissions, promote waste management, and conserve natural resources.