In the winter of North China, the use of a large amount of chlorine salt snow - melting agent makes the durability problem of highway concrete guardrail increasingly serious. Aiming at this problme, a simulation model of chloride ion corrosion resistance of concrete guardrail coating of highway bridge was established by COMSOL software using the chloride ion diffusion model as the theoretical basis. Results showed that the coating could significantly reduce the chloride ion concentration in the guardrail and thus improve its durability. As the coating thickness increased, chloride ion concentration decreased sharply first, and the decrease tendency gradually slowed down. With the decline of coating diffusion coefficients, the chloride ion concentration decreased significantly. Compared with the guardrail without coating, the ones applied with chlorinated polyvinyl chloride (CPVC) coating, chlorinated polyethylene (CPE) coating, chloroprene rubber latex (CR) coating and polyvinylidene chloride latex (PVDC) coating, which had different diffusion coeficients, realized a reduction of chloride ion concentration of at least 98%, 28%, 75% and 90%, respectively. Under the as - mentioned environment, CPVC coating possessed a better effect than other coatings. The research results could provide guidance for the actual construction projects.
