再生混凝土结构的氯离子侵蚀试验

Experimental on recycled concrete structure erosion by chloride ions and its control

为提高再生混凝土建筑物的安全性和耐久性.采用氯化物快速迁移法,研究氯离子对再生混凝土结构的侵蚀作用规律.研究成果表明:再生混凝土结构的水胶质量比、再生骨料取代率、矿物质掺量和硬化龄期等不同因素对抵抗氯离子侵蚀能力有不同程度的影响.控制水胶质量比、掺加无机功能材料和再生骨料强化处理,既可以改善界面过渡区的微观结构,也能够有效阻止氯离子的渗入,使得氯离子迁移系数DRCM降低;在结构表面涂刷保护层、适当增加混凝土保护层厚度和阴极保护,可以推迟钢筋产生电化学腐蚀时间,进而使再生混凝土结构抵抗氯离子侵蚀能力不断得到增强.该研究结果为再生混凝土在建设工程中的推广运用具有一定的实际指导意义.

To strengthen the safety of recycled concrete buildings and their durability, the paper studied the law of recycled concrete structure erosion by chloride ions, using the rapid chloride migration test. The results show that different factors, such as water-binder, replacement of recycled aggregate, ration of mineral substance and hardened time, have different effects on ability against erosion of concrete structures. The experiment also shows that controlling water-binder, adding inorganic functional material and enforcing recycled aggregate can improve the transitional microcosmic structures and stop chloride ions from sinking effectively as well, making chloride ions migration coefficient DRCM lower; painting protective layers properly, making the layers thicker and the protective of negative pole also can delay the time of electrical chemical erosion causing by steel bars. The ability of recycled concrete structures against chloride ions erosion can be further strengthened. The research has some practical meaningful guidance on spreading usage of recycled concrete in construction widely.