Evaluating the Resistance of Crumb Rubber and PVA Fiber-Enhanced Concrete to Acid Attack

Concrete durability is a critical concern due to prolonged exposure to aggressive environments. The use of crumb rubber (CR) derived from waste tires as a partial replacement for fine aggregate provides a sustainable solution for waste management; however, its influence on durability requires careful evaluation. This study investigates the combined effect of crumb rubber (10–30%) and polyvinyl alcohol (PVA) fibers (1–2%) on the acid resistance of concrete. Compressive strength, loss in compressive strength after acid exposure, weight loss, and change in specimen length were evaluated. Results show that compressive strength decreased with increasing CR content, ranging from 51.45 MPa for the optimum mix (10% CR and 1.5% PVA) to 35.17 MPa for mixes containing 30% CR. After sulfuric acid exposure, the optimum mix exhibited a strength reduction of approximately 10.65%. Weight loss and dimensional change increased with higher CR contents due to increased porosity and weaker interfacial bonding. The inclusion of PVA fibers improved crack resistance and partially mitigated degradation. Overall, moderate CR and PVA contents provide a balance between mechanical performance and acid resistance.