Mechanical Performance of Concrete with Partial Fine Aggregate Replacement Using Pulverized Waste Glass Bottles: A Comparative Study of Mix Grades

This study investigates the mechanical performance of concrete incorporating pulverized waste glass (PWG) as a partial replacement for fine aggregates in two distinct mix ratios: 1:1.5:3, representing higher-grade concrete, and 1:2:4, representing lower-grade concrete. Compressive strength tests were conducted at 7, 14, and 28 days on concrete samples with PWG replacement levels of 0%, 10%, 20%, 50%, 75%, and 100%. The results reveal that higher-grade concrete, with a greater reliance on aggregate interlocking and matrix bonding, is more sensitive to PWG content, showing significant reductions in compressive strength at a 100% replacement level. However, moderate replacement levels, specifically up to 75%, did not substantially affect long-term compressive strength, suggesting a tolerance for partial substitution in higher-grade mixes. In contrast, lower-grade concrete exhibited a notably positive response to PWG replacement, particularly at 75%, where compressive strength reached a peak of 32.15 N/mm². This outcome indicates that PWG can enhance the packing density of lower-grade mixes, compensating for its lack of angularity and bonding characteristics compared to natural aggregates. These findings underscore the potential of PWG as a sustainable and effective alternative to fine aggregates, particularly suited to applications in lower-grade concrete, while maintaining mechanical performance standards.