Durability Assessment of Sisal Fiber Reinforced-Mortar with Waste Glass Powder as A Partial Replacement for Cement in an Aggressive Environment

Mortar plays a crucial role in construction, serving as a binder in masonry, plastering, and repairs. However, durability remains a key challenge, especially under harsh environmental conditions. The potential of incorporating glass waste powder (GWP) and fibers in mortar is under explored. This study addresses that gap by evaluating how GWP (0–20%) and sisal fiber (1%) affect the performance of fiber-reinforced Mortar (FR-M). SEM and XRD analyses, following ASTM E1508 and C1365, were used to study microstructure and mineral phases. Mechanical testing (ASTM C109, C348) assessed compressive and flexural strengths at multiple curing ages, while sulfate resistance was evaluated using 5% MgSO₄ solution per ASTM C1012. Findings show optimal performance at 7.5% GWP with 18 MPa compressive and 6.7 MPa flexural strength. While higher GWP levels reduced strength, sisal fiber consistently enhanced mechanical properties. A mix with 15% GWP + 0.5% fiber showed excellent sulfate resistance—only 13.8% flexural and 14.8% compressive loss, with 0.096 mm (0.06%) expansion after 90 days—demonstrating superior durability and sustainability.