集料预处理对砂浆抗氯离子性能的提升

Effect of aggregate pretreatment on chloride resistance of mortar

港口混凝土面临氯离子侵蚀问题。为评估集料预处理与瞬时荷载下砂浆的抗氯离子渗透性能,将不同集料分别用矿粉和硅灰浆体包覆处理,改善集料的粗糙程度,并在瞬时荷载加载后测试样品的氯离子迁移系数。试验结果表明,集料经预处理后,界面性能得以改善,预处理集料配制砂浆的抗氯离子渗透性能优于未处理集料,且硅灰预处理效果优于矿粉;荷载作用越大,氯离子扩散系数越大,荷载作用后的硅灰预处理集料对应的抗氯离子渗透性能最优。

Port concrete generally suffers from chloride diffusion. To evaluate the resistance of mortar to chloride diffusion under different instantaneous loads after aggregate pretreatment, we coat the aggregate with slag powder and silica fume slurry respectively to change the roughness of aggregate. We then test the chloride migration coefficient of samples after an instantaneous load. The experimental results show that the interface performance of the aggregate is improved after pretreatment. The chloride diffusion coefficient of the mortar prepared by the pretreated aggregate is lower than that of the untreated aggregate, and the coating effect of silica fume is superior to that of slag powder. A larger load leads to a higher chloride diffusion coefficient, which endows the silica fume-coated aggregate after loading with the best resistance to chloride diffusion.