Investigation of the fresh, mechanical, durability, and microstructural properties of waste glass powder-modified cement paste

The challenge of solid waste management has become a major global concern, drawing extensive research interest internationally. In particular, waste glass has gained attention for its growing use in mortar and concrete production as a sustainable alternative, serving as a partial replacement for coarse aggregate, fine aggregate, and cement. However, research on the utilization of waste glass powder in cement paste and its effects on the fresh, mechanical, durability, and microstructural properties has been relatively limited. This article seeks to address this issue by focusing on the incorporation of waste glass powder as a partial replacement for cement across eight different ratios, ranging from 0 to 50%. The study explores the impacts of these ratios on paste flow, compressive strength, and flexural strength, as well as the microstructural properties of the cement paste. Furthermore, it examines how the inclusion of glass affects the reduction of paste strength when subjected to acidic conditions. The findings revealed that as the amount of waste glass powder in the cement mixture increase, its workability improved. Moreover, compressive strength increased with higher percentages of waste glass powder, peaking at 20%, after which it declined. However, the ideal dosage for achieving maximum flexural strength was identified as 15% waste glass powder. Additionally, incorporating waste glass powder into the cement paste mixtures significantly enhanced their resistance to acids, as evidenced by a 10% increase in residual compressive strength and a reduced weight loss compared to the control mixture. Finally, according to microstructural analyses, specifically XRD and SEM examinations, the inclusion of waste glass powder results in the generation of a greater amount of C-S-H gels during pozzolanic reactions. As a result, this enhances both the mechanical strength and durability of the cement paste.