Utilization of artificial interior stone sludge as fine aggregate in controlled low-strength material (CLSM)

Artificial interior stone, also known as imitation marble, is a representative high-end building interior material, the market share of which has been gradually increasing. Thus, the amount of waste sludge generated by its manufacture has also been rapidly increasing. However, because of a lack of a specific recycling plan, this waste is presently being disposed of in landfills. This study was conducted with the objective of recycling sludge into a fine aggregate for a controlled low-strength material (CLSM). The physicochemical properties of the sludge were investigated through various analyses. Subsequently, the material properties of sludge-containing CLSM in terms of compressive strength, bleeding rate, water absorption, and heavy metal content were examined. Through a combination of genetic algorithm-based machine learning and experimental results, a model equation that can predict the compressive strength of a CLSM specimen according to material composition was developed. This research presents a novel approach to recycling waste sludge from interior stone production as a fine aggregate for CLSM, addressing both environmental concerns and waste management in the industry.