Research on the durability of FRP-bonded concrete beams subjected to a performance probabilistic design method

Abstract

Abstract FRP-bonded concrete enhances the structural strength and extends the service life, yet durability challenges remain pronounced. Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP) are employed to bond precast cracked concrete beams. Three adverse environments are established: freeze-thaw cycle, sulfate erosion, and salt-freeze coupling erosion conditions. The degradation patterns of specimens under single erosion and coupled erosion environments are compared using electron microscopy, mass loss analysis, load-displacement curves, and bottom strain measurements. The disparities in degradation mechanisms between coupled and single erosions are also examined. The outcomes demonstrate that the degradation from salt-freeze coupling erosion surpasses the cumulative effect of individual erosion. The mechanism behind salt-freeze coupling erosion involves sulfate exacerbating the irregular deterioration of FRP-bonded concrete beams induced by freeze-thaw cycles. The calculated error rates for load strength in adverse environments using the probabilistic design methods are 1.22%, 2.86%, and 2.13%, respectively, all within the 3% threshold, indicating a high level of predictive accuracy. Ultimately, predictive models for the strength of FRP-bonded concrete beams are developed under the three adverse environmental conditions.