硫酸盐侵蚀与冻融耦合作用下混凝土损伤研究

Study on the damage of concrete under the couple action of sulfate corrosion and freeze-thaw

通过试验研究了先硫酸盐侵蚀后冻融、先冻融循环后硫酸盐侵蚀、硫酸盐侵蚀与冻融循环交互作用3种方式下混凝土质量损失率及相对动弹性模量的变化。结果表明,先硫酸盐侵蚀后冻融工况下混凝土劣化程度大于单一冻融工况,先冻融循环后硫酸盐侵蚀工况下混凝土劣化程度大于单一硫酸盐侵蚀工况,硫酸盐侵蚀与冻融交互作用工况下混凝土劣化程度大于2种工况分别作用下劣化程度的叠加。硫酸盐侵蚀与冻融耦合作用下混凝土劣化进程明显加快,硫酸盐侵蚀与冻融耦合作用过程中形成超叠加效应,二者相互促进,相互影响。

Through experiments,the change of concrete mass loss rate and relative dynamic elastic modulus under three dif-ferent ways of frost -thaw after sulfate attack,sulfate attack after the freeze -thaw cycle and interaction of sulfate erosion and freeze-thaw cycle were investigated. The results show that the deterioration degree of concrete under freeze-thaw after sulfate at-tack condition is higher than that of single freeze-thaw condition. The deterioration degree of concrete under sulfate attack after freeze-thaw cycle condition is higher than that of single sulfate attack condition. The deterioration degree of concrete under the interaction condition of sulfate erosion and freeze-thaw is greater than that of the superposition degradation of the two conditions separately. The degradation process of concrete under the coupling action of sulfate attack and freeze-thaw is obviously accelerat-ed. The super-superposition effect is formed during the coupling process between sulfate erosion and freeze-thaw. Both of them promote each other and affect each other.