Bond performance of GFRP bars embedded in steel-PVA hybrid fiber concrete subjected to repeated loading

The bond performance of glass fiber-reinforced polymer (GFRP) bars embedded in steel fiber-PVA hybrid fiber concrete plays an important role in their integration. In the present work, hybrid fiber concrete in different volume ratios of hybrid fibers with GFRP was investigated. Pullout tests with two amplitude regimes were conducted on hybrid fiber concrete specimens integrated with GFRP bars to investigate its ultimate bond strength, bond-slip curve, energy dissipation characteristics, and bond stiffness. The results indicate that when the total fiber volume ratio was fixed at 0.9%, the bond strength between the GFRP bars and hybrid fiber concrete increased gradually as the steel fiber volume increased, and the energy consumption increased gradually during the pullout. The slip corresponding to the ultimate bond strength under variable-amplitude repeated loading is in good agreement with the experimental results under monotonic loading. The specimen P1S8 (0.1% PVA, 0.8% steel fiber) hybrid exhibited sufficient energy dissipation capacity and deformation capacity under repeated loads, and the bond stiffness is relatively higher and more stable during the loading and unloading stages.