Chloride Transport in Unsaturated Concrete under Temperature and Sustained Compressive Loading

The distribution of chloride concentration in unsaturated concrete under the combined influence of temperature and sustained loading is crucial for evaluating the durability of loaded concrete structures. This study conducted accelerated chloride diffusion experiments on unsaturated concrete specimens subjected to varying temperatures and sustained compressive loading. The chloride concentration distribution patterns were analyzed, and a diffusion coefficient model was developed considering the effects of temperature and sustained compression. The accuracy of the numerical model was validated through experimental data. The results indicated that peak chloride concentration increased with rising temperature. When both temperature and sustained compressive loading increased simultaneously, chloride concentration initially decreased before increasing. The reduction in chloride concentration given these conditions was less significant than when concrete was subjected solely to sustained compressive loading. Additionally, when the sustained compressive load exceeded 0.3fc (compressive strength of concrete), the depth of the convection zone increased with compressive stress. The proposed model demonstrated an average accuracy improvement of 15.83% compared to existing models.