Service Life Prediction of RC Bridge Structures Exposed to Chloride Environments

Abstract

For a long-span coastal bridge structure, the corrosion initiation time is controlled by the speed of chloride ions transfer and the depassivation process within the structure. These processes are significantly influenced by the actual variation of the environmental conditions on the concrete surface throughout its service life. From the regional climate characteristics through local climate conditions, the microclimate variation on the concrete surface is studied in this research. A set of realistic environmental condition profiles is proposed, based on the exposure conditions and the material properties of the components. Moreover, a 2D integrated corrosion performance assessment model is constructed to capture the change in environmental conditions and simulate the coupled diffusion process and the corrosion performance in the time domain. Two typical locations (Hong Kong and Michigan) are chosen as numerical examples for implementing the proposed corrosion performance assessment model, and control of the environmental factors of the various chloride exposures is highlighted. These factors are used to construct an integral empirical equation together with the general critical material and geometrical parameters.