电阻率法评价膨胀土改良的物化过程

掺石灰、粉煤灰是工程中通常采用的改良膨胀土的方法。土电阻率是土的基本物理指标之一，其变化可反映土的其他物理性质指标的变化。通过掺灰改良膨胀土不同养护龄期下的电阻率测试以及膨胀量、膨胀力及无侧限抗压强度等试验研究，探讨了掺灰改良膨胀土养护过程中的物理化学反应过程。根据养护过程中的电阻率随龄期的变化规律，可将改良膨胀土的物理化学反应过程划分为瞬时反应阶段、主体反应阶段、残余反应阶段和稳定阶段4个不同阶段。针对改良膨胀土质量控制和评价体系中存在的不足，提出了基于电阻率指标的改性膨胀土的质量评价方法，通过试验证实了该方法的有效性和实用性。

Evaluation of physicochemical process in stabilized expansive soils using electrical resistivity method

The commonly used method to control and stabilize expansive soils is to add stabilizing agents, such as lime, fly ash or cement. Electrical resistivity of soil can be considered as a proxy for the spatial and temporal variability of many other soil physical properties. Because the method is non-destructive and very sensitive, it offers a very attractive tool for describing soil physical properties. The electrical resistivity of lime or fly ash treated expansive soils changes with the development of physicochemical process in the stabilized soils. The purpose of this work is to evaluate the potential application of electrical resistivity measurements for detecting the physicochemical process in lime or fly ash treated expansive soils. A series of experimental programs are performed to study the relationships among electrical resistivity, swell potential, swelling pressure, unconfined compressive strength during curing time. Four different zones named instantaneous reaction, principal reaction, residual reaction and steady phases are divided. A new, simple electrical resistivity method is put forward to evaluate the swell potential and shear strength of stabilizer-treated expansive soils. Its practical implication is validated by experiment results.