温度和氯盐对混凝土硫酸盐化学腐蚀的影响

Influence of temperature and chloride on chemical corrosion of concrete in sulphate

为揭示混凝土在不同硫酸盐腐蚀环境下的损伤过程及腐蚀机理,进行了硫酸盐浸泡实验,研究了在复合溶液浸泡作用下混凝土的抗压强度演变、腐蚀产物类型及硫酸根离子反应能力.结果表明:混凝土在硫酸钠溶液中抗压强度先增加后降低,且主要腐蚀产物是钙矾石和石膏.在复合溶液腐蚀环境下,腐蚀产物以钙矾石为主,且混凝土亚微观缺陷减少6.46%.当提高腐蚀溶液温度至50℃时,混凝土的抗压强度演变速度加快,硫酸根离子反应能力提高20%,腐蚀产物以石膏为主.

In order to clarify the damage process and corrosion mechanism of concrete under different sulphate corrosion environments, the sulphate immersion experiments were performed. In addition, the compressive strength evolution, corrosion product type and sulphate reaction capacity for the concrete under the action of composite solution immersion were investigated. The results show that in the Na： SO4 solution, the compressive strength of the concrete firstly increases and then decreases, and the main corrosion products are ettringite and gypsum. Under the corrosion environment of complex solution, the main corrosion products are ettfingite, and the sub-microscopic defects in the concrete decreases by 6.46%. When the temperature of corrosion solution increases to 50 ~C, the evolution speed of compressive strength increases, the sulfate reaction capacity increases by 20%, and the corrosion products are mainly gypsum.