干湿循环机制下类岩-HDSC组合体的氯盐单向侵蚀试验及机理研究

Unidirectional chloride salt erosion test and mechanism study of rock-HDSC assemblage under dry-wet cycle mechanism

高延性喷射型混凝土(HDSC)是一种新型的工程凝胶复合材料,用于隧道、矿井等的修复工作。以10%质量分数的氯盐溶液为侵蚀介质,对类岩-HDSC组合体进行为期200 d干湿循环试验,探究了干湿循环条件下氯离子对类岩-HDSC组合体的单向侵蚀机理。试验结果表明:由于氯离子的结合作用,并且Friedel盐和氯盐晶体对组合体内部孔隙的填充效应,导致组合体破坏程度随循环次数的增加而增大,且内部损伤出现的时间会随着循环次数的增加而前移;单轴压缩下组合体的弹性能与耗散能比例总体呈负相关;氯盐侵蚀深度增长速率后期受纤维影响较大,纤维具有一定的抗氯离子侵蚀能力。

High ductility shotcrete(HDSC)is a new type of engineering gel composite material,which is used for the repair of tunnels and mines.The dry-wet cycle test ofrock-HDSC combination was carried out for 200 days with 10%(by mass)fraction of chloride salt solution as the erosion medium,and the unidirectional erosion mechanism of chloride ion on rock-HDSC combination under dry-wet cycle conditions was explored.The test results show that due to the binding effect of chloride ions and the filling effect of Friedel salt and chloride crystal on the internal pores of the combination,the damage degree of the combination increases with the increase of the number of cycles,and the time of internal damage will move forward with the increase of the number of cycles.The elastic energy of the combination under uniaxial compression is negatively correlated with the proportion of dissipated energy.The growth rate of chloride corrosion depth is greatly affected by fiber in the later stage,and the fiber has certain resistance to chloride ion erosion.