Bai Keming

Road, Bridge, and River-Crossing Engineering, Shandong University of Science and Technology

Abstract：

Under the coupled action of hygrothermal conditions, freeze-thaw cycles, and transient vehicular impact loads, concrete bridges are prone to strength degradation, crack propagation, and reinforcement corrosion, resulting in the continuous deterioration of structural load-bearing performance. Through theoretical analysis and a systematic review of existing experimental results, this paper investigates the evolution of the mechanical properties of concrete under multi-field coupling, reveals the synergistic damage mechanisms caused by hygrothermal conditions, freeze-thaw cycles, and transient impacts, and proposes targeted performance-enhancement measures from the perspectives of materials, structural configuration, and protection. The results show that coupled environments produce a significant damage-amplification effect on concrete bridges, and the deterioration rate is much higher than that under a single environmental factor or dual-factor coupling. By optimizing concrete mix proportions, improving structural detailing, applying surface-protection technologies, and implementing carbon-fiber-reinforced polymer (CFRP) strengthening, the structural deterioration process can be effectively slowed, and the durability and load-bearing capacity of bridge structures can be significantly improved. The findings provide theoretical references and engineering support for the design optimization and maintenance strengthening of concrete bridges in complex service environments.

Key Words：

concrete bridge; hygrothermal environment; transient load; coupled action; mechanical properties; performance enhancement