冻融循环过程中砂浆电阻率变化及其机理分析  

Mechanism Analysis and Change of Mortar Electrical Resistivity during Freezing-thawing Cycles

作　　者：侯云芬[1] 王玲[2] 吴越恺[1] 王振地[2] 

机构地区：[1]北京建筑大学,北京100044 [2]中国建筑材料科学研究总院,北京100024

出　　处：《粉煤灰综合利用》2015年第1期3-5,10,共4页Fly Ash Comprehensive Utilization

基　　金：国家973项目课题"荷载-冻融-盐溶液侵蚀协同作用下钢筋混凝土破坏机理研究(2012CB724602)

摘　　要：混凝土或砂浆内部孔隙中液相的变化直接影响其导电特性,在冻融循环过程中,随着温度-湿度的变化,砂浆孔隙不仅液相离子浓度会变化,而且还会结冰,最终引起其电阻率变化,具体表现为：无论是降温段,还是升温段,电阻率均随温度降低而增大;在低温区段,电阻率变化幅度较大,在高温区段,电阻率变化幅度很小,且在结冰温度范围内出现了突变现象;在每一个冻融循环内电阻率均出现滞回现象,且滞回环并不饱满,在-10℃~5℃温度（即结冰和融化温度）范围内曲线出现了转折;随冻融循环次数的增加,电阻率呈现增大趋势,尤其是温度最低点时的电阻率增加幅度较大。The change of fluid in voids of concrete and mortar will affect their electrical resistivity. During freezing-thawing cycle, the concentration of fluid in voids changes with the change of temperature-humidity, even freeze to result in the change of electrical resistivity. The electrical resistivity increases with the reducing of temperature ; and the rangeability of electrical resistivity is bigger in low temperature period, but it is smaller in high temperature period. The electrical resistivity shows sudden change during freezing-temperature period, and arise the hysteretic phenomenon in each freezing-thawing cycle. The electrical resistivity increases with increasing of freezing-thawing cycle index, especially at the lowest temperature.

关 键 词：电阻率 冻融循环 湿度 变形 

分 类 号：TU528.1[建筑科学—建筑技术科学]