Multi-factor sensitivity analysis of chloride ingression: A case study for Hangzhou Bay Bridge

The transport of chloride into concrete is affected by many factors, including temperature, relative humidity, load cracks, and material properties. The purpose of this paper is to analyze the influence of various factors on the chloride ingression process through a case study for Hangzhou Bay Bridge located in marine environment. Firstly, based on the concentration of free chloride in pore solution, a porous media diffusion model is derived, considering the chloride adsorption term. Then, chloride adsorption isotherm, time-varying diffusion coefficient, temperature, relative humidity, and macroscopic cracks are simulated respectively by the porous media diffusion model. The main conclusions are as follows: (1) The chloride adsorption effect and time-varying diffusion coefficient have a great influence on the numerical results, which cannot be ignored in any case. (2) The natural temperature and relative humidity conditions of the case have a small effect on the simulation results. (3) Under the marine atmospheric environment, the macroscopic load cracks have a small influence on chloride ingression in the long term. •A transport model based on free chloride in concrete pore solution is established.•Chloride adsorption isotherm of concrete is assumed to be a transient process.•Effect of air relative humidity on concrete saturation is analyzed and simplified.•A none flux boundary condition is applied to the opening of macro load crack.•Five years of natural air temperature and relative humidity data were employed.