In-service performance assessment of fire-corrosion damaged cables of bridges

Cable-supported bridges are prone to fire hazards, and the corrosion within further compromises their structural integrity. The present study provides a novel framework for assessing fire-corrosion damage of steel wires currently in use. The relations and failure modes of steel wires under coupled effects of fire-corrosion are established by conducting the tensile test utilizing the replaced steel wires after the fire. Experimental studies found that the deterioration tendency of in-service steel wires after the fire is consistent with that of intact ones, while the corrosion level and position of steel wire have a significant impact on its ultimate strain. To predict the residual mechanical properties of cables after the fire-corrosion coupled damage, a comprehensive database of steel wires properties after the fire is established, and then a data-driven surrogate model is proposed. Finally, four grades are suggested to evaluate various damage degrees of in-service cables under corrosion and fire. The findings can provide bridge owners with guidance on how to replace or repair the damaged components after accidents or natural disaster, thereby increasing the reliability and lifespan of bridges and decreasing the costs associated with maintenance, reconstruction, and replacement.