Effect of Waste Glass Powder Replacement of Hydraulic Lime on Properties of Natural Hydraulic Lime Mortars

This paper investigates the effects of the partial replacement of natural hydraulic lime (NHL) with waste glass powder (GP) on the physical, mechanical, and microstructural properties of NHL mortars. In the experimental study, five mixtures containing up to 50% GP were prepared to evaluate its effect on the flow, carbonation, unit weight, water absorption, porosity, ultrasonic pulse velocity, capillary water absorption, compressive strength, and microstructure of NHL mortars. The experimental results suggest that the partial replacement of NHL with GP significantly affects the properties of NHL mortars. A reduction in compressive strength was observed with increasing GP content in mortars at both early and later stages. Nevertheless, the compressive strength difference between samples containing 50% GP and the reference was found to be relatively minor at 91 days, implying an enhanced pozzolanic reaction over time. The incorporation of GP improved the consistency and capillary water absorption of mortars, while the opposite was observed for ultrasonic pulse velocity, porosity, and water absorption. The microstructural analysis revealed distinct changes in the structure of samples incorporating GP. The partial substitution of hydraulic lime with GP could be beneficial in reducing the CO₂ emissions of NHL mortars.