Durability and Microstructural Analysis of Mortar Incorporating Glass Powder and Copper Slag

Untreated solid waste presents significant environmental challenges, particularly in areas surrounding industrial activities. This study investigates a sustainable solution through the utilization of industrial by-products—copper slag from the iron industry and waste glass powder from soda-lime glass bottles—in mortar production. Mortar mixtures were prepared with partial replacements: cement was replaced with glass powder (GP) at 5%, 10%, 15%, 20%, and 25%, while fine aggregate was replaced with copper slag (CS) at 0%, 10%, 20%, 30%, 40%, and 50%, maintaining a cement-to-fine aggregate ratio of 1:4. Key properties were assessed through comprehensive laboratory tests, including compressive strength; shear bond strength, drying shrinkage, flowability, and water absorption. Microstructural properties were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). Results indicate an initial decrease in compressive strength at lower replacement levels, followed by a significant improvement that surpasses the reference mortar. Optimal performance was achieved with 20% copper slag as sand and 10% glass powder as cement, improving multiple properties despite variations in drying shrinkage and shear bond strength. This research underscores the potential of glass powder and copper slag to enhance the performance and sustainability of construction materials, providing an effective pathway for waste valorization in the construction industry.