Production of sustainable and structural fiber reinforced recycled aggregate concrete with improved fracture properties: A review

In recent years, due to the ever-increasing demand of concrete the need for sustainable and economically feasible structural concrete has obtained special attention of both researchers and various construction industries. Fiber reinforced recycled aggregate concrete (FRAC) is one such material that has gained popularity since the beginning of twenty-first century due to its high strength, eco-friendly, and cost-effectiveness benefits. Fiber reinforcement in recycled aggregate concrete (RAC) tends to reinforce and retard the crack propagation and thus results in ductile behavior of cementitious matrix. Despite an increasing interest in the use of FRAC, there are still some doubts about the dosages and reinforcing effects of fibers in RAC containing recycled concrete aggregate (RCA) in partial or complete replacement mode. This article presents a comprehensive review on the workability and mechanical properties of FRAC. Specifically, the aim of this review study is to highlight the most promising and feasible strength enhancement methods for the FRAC mainly using steel fiber (SF), polypropylene fiber (PPF), basalt fiber (BF), and glass fiber (GF). Furthermore, it comprehensively reviews the effect of these fibers on the flowability, compressive strength, flexural strength, splitting tensile strength and other durability aspects of the FRAC. It also presents the relationship among the volume fractions of fiber, percent replacements of RCA and strength enhancement in RAC which may help in identifying the optimum dosage of each fiber for the strength improvement in FRAC. The effective utilization of these fibers will enable the full-scale utilization of RCA in the fabrication of sustainable and structural concrete and will help the construction sector in implementing the concept of circular economy model.