Experimental Study on the Bond Performance Between Corroded Steel and Basalt Fiber Reinforced Concrete

To elucidate the bond degradation mechanism of basalt fiber reinforced concrete (BFRC) under the coupled effects of water cooling after elevated-temperature exposure and steel corrosion, 150 eccentric pull-out specimens were designed and fabricated to systematically investigate the influence of basalt fiber (BF) volume fraction, corrosion degree, and water cooling on bond performance. Test results indicate that the bond failure mode of the specimen changes after exposure to 600℃. Both water cooling and corrosion significantly deteriorate bond strength, whereas the incorporation of BF effectively delays the development of interfacial damage. When the BF volume fraction is 0.10%, the bond strength of BFRC after water cooling at 400℃ increases by 45.7% compared with that of ordinary concrete. Grey relational analysis indicates that among the coupled factors, water cooling is the dominant parameter governing bond strength, followed by the corrosion degree and BF volume fraction. Microstructural characterization (SEM-EDS) further reveals the microstructural features and elemental variations within the interfacial transition zone of BFRC. Finally, based on regression analysis of compressive strength data, a predictive formula for BFRC bond strength under the combined effects of water cooling and corrosion is established, and a two-stage bond-slip constitutive model describing the bond stress of BFRC is proposed.