电阻率法研究早期水泥净浆孔结构的演变过程

采用无电极电阻率法原位连续监测3种水灰比（0.23、0.35和0.53）水泥净浆早期水化过程中电阻率的变化全过程,同时结合等温量热仪测试的水化程度,建立水泥净浆随时间发展过程中浆体电阻率与孔结构发展的定量关系。结果表明：根据电阻率及其微分曲线的变化规律可以把水泥水化过程分为4个阶段：溶解期、诱导期、加速期和减速期。水灰比越低,毛细孔隙率和收缩因子变小,曲折因子变大,致使浆体电阻率升高,而孔溶液电阻率却下降。

Resistivity Method for Monitoring the Early Age Pore Structure Evolution of Cement Paste

The changes of electrical resistivity with time of cement pastes with water to cement ratio of 0.23,0.35 and 0.53 were in situ continuously monitored by using electrodeless resistivity apparatus.Isothermal conduction calorimeter was also used to measure the hydration degree.The quantitative relationship between electrical resistivity evolution of paste and development of pore structure was proposed during hydration process.The results show that four stages（dissolution,induction,acceleration and deceleration） are identified according to the characteristics of electrical resistivity and its differential resistivity curves.In addition,a lower water to cement ratio shows a smaller capillary porosity and constriction factor as well as a higher tortuosity factor,resulting in a higher electrical resistivity of bulk paste,and the reverse phenomenon is observed with the electrical resistivity of pore solution.