【摘要】 用无接触电阻率测定仪测定了不同水灰比水泥浆基体的电阻率随时间变化的特征曲线ρ(t)-t,研究了普通硅酸盐水泥的水化特性。研究表明:基体电阻率P(t)是液相电阻率ρ0(t)和孔隙率φ的函数。实验结果说明:根据基体电阻率曲线的特征点将水泥水化过程划分为溶解期、诱导形成期和诱导期、凝结硬化期3个阶段。钙矾石包裹层的形成导致水化进入诱导期,渗透压导致包裹层的破裂,使水化进入凝结硬化期。溶解期电阻率的下降主要与水泥浆体中液相离子浓度的增加相关。诱导形成期和诱导期电阻率变化小,此时液相离子浓度和孔隙率的变化都较小,凝结硬化期电阻率的上升主要与水泥浆体孔隙率的下降相关。更多还原

【Abstract】 The electrical resistivities p(t) of cement pastes with different water cement ratios were measured in a non-contacting electrical resistivity measurement device. The hydration process was revealed. The electrical resistivity p(t) is a function of electrical resistivity of liquid phase ρ0(t) and porosity The results show that the hydration process can involve the dissolving period, the induction-forming and induction period, and the setting-hardening period as well. The formation of ettingite coatings results in the initial step of induction period and the breakage of the coatings due to the osmotic pressure leads to the initial step of setting and hardening period. The electrical resistivity decreases with increase of the ion concentration in the pore solution at the dissolving period. There is a slight variation on the electrical resistivity in the pore solution, and also on the ion concentration and the porosity at the induction-forming and induction period. The electrical resistivity increases with decrease of the porosity at the setting-hardening period.更多还原