Research on Long‐Term Transverse Shear Behavior Prediction of Steel Fiber‐Reinforced‐Carbon/Glass Hybrid Composite Bars in Concrete Structures

ABSTRACT To investigate the transverse shear properties of steel fiber‐reinforced‐carbon/glass hybrid composite (S‐CG HFRP) bars in an alkaline environment, an experiment on transverse shear properties of S‐CG HFRP bars under simulated concrete pore solutions was conducted. The effects of steel fiber content ( V _S ), the ratio of carbon‐glass fiber content ( V _C / V _G ), and temperature on the transverse shear properties were examined, and the deterioration mechanism was revealed through optical microscopic observation. The results indicate that adding steel fibers significantly improved the shear resistance and ductility of S‐CG HFRPs. In addition, as V _C / V _G decreased, the transverse shear stress retention declined obviously, which was attributed to the alkaline resistance of glass fibers being worse than that of steel and carbon fibers in concrete environments. However, the transverse shear strain retention was observed to be negligibly influenced by V _C / V _G . The temperature exhibited a substantial influence on the durability of S‐CG HFRP bars, as elevated temperatures accelerated resin degradation and glass fiber decomposition. After 63 days of alkaline corrosion at 20°C, 40°C, and 60°C, the transverse shear strength retention of specimens with V _S of 30% and V _C / V _G of 1 / 6 was 97.02%, 91.65%, and 84.8%, respectively. The ester group in epoxy resin and the SiO ₂ of glass fibers in S‐CG HCBs were prone to react with OH ⁻ in concrete environments, which deteriorated the transverse shear properties. Considering variations in V _S , V _C / V _G , and ambient temperature, this study proposed a prediction model for evaluating the transverse shear strength of S‐CG HFRP bars in concrete environment.