Reinforced concrete structures in an unsaturated state experiences significant degradation when exposed to combined chloride and sulfate attack in marine environments. For evaluating durability and predicting service life of reinforced structures, it is crucial to better understand ions diffusion, porosity variation and water saturation of concrete. Considering effect of porosity and water saturation degree on chloride diffusivity, a new diffusion-reaction model was established to investigate how concrete degrades exposed to the severe marine environment. The model was validated using experimental results from both hydrophobic and plain concrete that had undergone a 14-month exposure test at the Qingdao Wheat Island exposure station. The simulation results of the multi-ions model showed that both plain concrete and hydrophobic concrete experienced maximum reduction of chloride concentration of about 68% when compared to concrete exposed to the unsaturated condition.

处于不饱和状态的钢筋混凝土结构在海洋环境中受到氯化物和硫酸盐的联合侵蚀时会经历显着的退化。为了评估钢筋结构的耐久性和预测使用寿命，更好地了解混凝土的离子扩散、孔隙率变化和水饱和度至关重要。考虑孔隙率和水饱和度对氯化物扩散率的影响，建立了一种新的扩散反应模型来研究混凝土在恶劣海洋环境下的降解情况。该模型使用在青岛麦岛暴露站进行了 14 个月暴露测试的疏水混凝土和普通混凝土的实验结果进行了验证。多离子模型的模拟结果表明，与暴露在非饱和条件下的混凝土相比，素混凝土和疏水混凝土的氯化物浓度最大降低了约68%。