硫酸钠和硫酸镁溶液中混凝土腐蚀破坏的机理

MECHANISM OF CONCRETE DESTRUCTION UNDER SODIUM SULFATE AND MAGNESIUM SULFATE SOLUTION

通过干湿循环的实验室加速腐蚀,探索混凝土在硫酸钠或硫酸镁溶液中的腐蚀破坏机理。测试了腐蚀破坏过程中混凝土的抗压强度、抗折强度、超声波在混凝土中的传播速度以及饱和面干吸水率,同时还分析了不同腐蚀阶段水化产物的微观结构。结果表明:混凝土的硫酸盐腐蚀破坏是一个复杂的物理化学过程,不同种类的硫酸盐溶液中混凝土的破坏机理不尽相同。在腐蚀后期硫酸钠溶液中混凝土各性能指标的变化幅度比在硫酸镁溶液中的大,这是经过一段时间的干湿循环之后化学侵蚀与物理作用即盐的结晶相互作用的结果。

Based on accelerated deterioration experiment techniques, the mechanism of concrete destruction under sodium sulfate and magnesium sulfate solution was studied. The compressive strength and the bending strength, the ultrasonic velocity passing through the concrete and the water absorption of the dry saturation surface were detected, also, the microstructures of concrete at different corrosion degree were studied. The results show that the destruction mechanism in different sulfate solutions are in different types. The change range of index of concrete in sodium sulfate solution is more than that in magnesium sulfate solution at the late stage of the attack process due to the interaction of chemical attack and physical action after a period of dry-wet cycle.