The main aim of the present research is to determine the degradation mechanisms of cast-in-situ concrete subjected to sulphate-chloride combined attack. Concrete specimens were prepared and then put into sulfate or sulfate-chloride mixed solutions. The sample dimension, mass, compressive strength, and sulfate concentration of the specimens were continuously monitored. The microstructures and the complex mineral composition of the concrete were analysed after 12 months of exposure to the corrosive environments. The results show that cast-in-situ concrete suffers more severe damage and greater strength loss when subjected to sulfate-chloride combined attack than when subjected to sulfate only. The diffusion and accumulation of sulfates are accelerated by the coexisting chlorides, especially in the early stages. The coexistence of chlorides in sulfate environments accelerates the degradation of cast-in-situ concrete induced by sulfate attack. The different performances against sulfate-chloride combined attack between cast-in-situ and precast concrete were mainly due to the degradation behaviour at the early stage.

本研究的主要目的是确定现浇混凝土在硫酸盐-氯化物共同作用下的降解机理。准备混凝土标本，然后放入硫酸盐或硫酸盐-氯化物混合溶液中。连续监测样品的尺寸，质量，抗压强度和硫酸盐浓度。在暴露于腐蚀性环境12个月后，分析了混凝土的微观结构和复杂的矿物成分。结果表明，与仅经受硫酸盐作用相比，现浇混凝土在遭受硫酸盐－氯化物联合侵蚀时遭受的破坏更严重，强度损失更大。氯化物的共存促进了硫酸盐的扩散和积累，特别是在早期阶段。氯化物在硫酸盐环境中的共存会加速由硫酸盐侵蚀引起的现浇混凝土的降解。现浇混凝土和预制混凝土在硫酸盐-氯化物联合侵蚀方面的不同性能主要是由于早期的降解行为。