Investigation on the fracture performance of macro fiber-reinforced concrete with waste glass fiber polymer

Mechanically recycled glass fiber-reinforced polymer (GFRP) presents a sustainable approach for reducing the environmental footprint of waste FRP composites. In this work, recycled GFRP is processed into macro fibers for the production of macro fiber-reinforced concrete (MFRC), and its fracture behavior is examined using edge-notched disc bend (ENDB) specimens with a through-thickness pre-crack configuration. The fracture toughness and total fracture energy are evaluated under Mode I, II, III, and mixed-mode loading conditions. The results indicate that the incorporation of recycled GFRP macro fibers significantly improves the fracture resistance compared to plain concrete, with optimal performance achieved at a fiber volume fraction of approximately 1.5 %. During crack propagation, fiber bridging enhances crack-path tortuosity and energy dissipation. Under mixed-mode loading, both the fracture load and fracture energy show a non-linear relationship with span length. This study employs a through-thickness-cracked (TTC) pre-crack configuration in ENDB specimens to evaluate the fracture toughness of MFRC. By eliminating initial fiber bridging at the crack front, the measured values provide a conservative yet reliable basis for design. © 2026 Elsevier Ltd.