Influence of UHMWPE fibers on the flexural performance of GFRP reinforced concrete slabs

This research investigates how varying volume fractions of ultra-high molecular-weight polyethylene (UHMWPE) fibers impact the flexural performance of concrete slabs reinforced with glass fiber-reinforced polymer (GFRP) bars. By conducting static bending tests on six distinct concrete slabs with three loading points, the study examines the effects of UHMWPE fibers on factors such as deflection, ultimate bearing capacity, crack distribution, and longitudinal steel strain in steel and GFRP-reinforced concrete slabs. The results of the study suggest incorporating UHMWPE fibers can effectively enhance the typically brittle failure mode of GFRP bars and improve the ultimate bearing capacity of GFRP bar-concrete slabs. Specifically, the research highlights that a 0.5% UHMWPE fiber concentration demonstrates the most significant inhibitory effect on mid-span deformation and longitudinal reinforcement strain growth in GFRP-reinforced concrete slabs. However, this inhibitory effect diminishes as the volume fraction of UHMWPE fiber reaches 0.7%. Finally, a calculation method for the flexural load-carrying capacity of GFRP-reinforced UHMWPE fiber concrete slabs is proposed, along with a coefficient k (set at 0.8) representing the effect of UHMWPE fibers on the tensile strength of concrete.