Effect of Single and Hybrid Fibers on Mechanical Properties of High-Strength Self-Compacting Concrete Incorporating 100% Waste Aggregate

AbstractIn this research, a combined experimental and analytical program was conducted to study the effect of the single and hybrid fibers [polyvinyl alcohol (PVA) and steel] on the material characteristics of the sustainable high-strength self-compacting concrete incorporating a 100% replacement ratio of aggregate with granite industry by-product. The experiment includes 13 mixture compositions to understand mechanical and impact properties. The analytical investigation comprises statistical analysis of impact behavior, optimized mix compositions, and regression analysis between mechanical properties. The sustainable cementitious composites were made with 100% recycled fine aggregate, different volume fractions of PVA and steel fibers (0%, 0.5%, 1.0%, 1.5%, and 2.0%), and a constant proportion of Class F fly ash as partial replacement of cement. Mechanical properties of hardened concrete were studied in terms of compressive strength, splitting tensile strength, and three-point flexural tests. Specimens were subjected to repeated drop-weight, ultrasonic pulse velocity, and water absorption tests to determine impact resistance, integrity, and durability. It was discovered that incorporating fibers into fully recycled fine-aggregate concrete improves the material’s properties, which was found to be highly dependent on the use of single or hybrid fibers, their types, and their content. The energy-absorbing and energy-dissipating capability of samples was improved remarkably with the addition of fiber volume dosage. The best efficiency was for the mixture with 1.5% hooked-end fibers according to the higher values of mechanical and impact properties and the lower cost.