Evaluation of Cement Hydration Properties of Cement-Stabilized Lead-Contaminated Soils Using Electrical Resistivity Measurement

In this study, electrical resistivity was related to the fundamental geotechnical properties of cement solidified/stabilized heavy metal-contaminated soils. Lead-contaminated soils were artificially prepared with various concentrations and treated by portland cement Type I at three content levels. The compacted cylindrical specimen was prepared with a diameter of 50 mm and height of 100 mm. The apparent electrical resistivity, electrical conductivity of pore fluid, unconfined compressive strength, and water contents were measured at different curing times. The result shows that the apparent electrical resistivity increases with the increase of curing time and the decrease of porosity and saturation degree as a result of cement hydration development. The effects of lead concentration, cement content, and curing time on the apparent electrical resistivity were discussed. The cementation index m was used to evaluate the cementation degree of cement-treated lead-contaminated soils. Lead pollutant at high concentrations could suppress or retard the hydration of solidified/stabilized soils. Electrical resistivity measurements can be used as a nondestructive method to evaluate the hydration development of solidified/stabilized leadcontaminated soils. (C) 2011 American Society of Civil Engineers.