Analysis of Factors Affecting the Durability of Concrete in Road Bridges

摘要

Abstract

 Road bridges are a key component of transportation infrastructure, and the durability of concrete structures is directly related to engineering service life and operational safety. Based on a literature review, field investigation, and experimental analysis, this paper explores the major factors affecting the durability of concrete in road bridges. At the environmental level, variations in temperature and humidity, chemical corrosion, and freeze–thaw cycles can all impair structural performance, while chloride ion erosion and concrete carbonation are the primary causes of reinforcement corrosion. At the material level, the water–cement ratio, aggregate quality, and the type and dosage of cement and admixtures determine the compactness and impermeability of concrete. At the construction level, improper mixing, pouring, and curing can easily lead to internal defects and accelerate the intrusion of harmful substances. At the design level, the mix proportion, structural form, and concrete cover thickness play decisive roles in durability. Taking a group of expressway bridges as the object of long-term observation, this study constructs a concrete durability evaluation model under multi-factor coupling and introduces the concept of life-cycle design. The results confirm that the selection of a low water–cement ratio, high-quality aggregates, and appropriate mineral admixtures, together with strict construction quality control and standardized curing, can significantly improve concrete durability. The findings provide an important reference for bridge structural design, operation, maintenance, and conservation.