关键词: 塑性混凝土墙;铅离子;混凝土强度;渗透系数;pH;电导率;

Abstract: Plastic concrete cutoff walls are widely used in the remediation of industrial contaminated sites.Considering the universal existence of lead ions in contaminated sites，the hydration-carbonation reaction of cement and the bentonite-contamination solution interaction are both affected by lead ion，further the strength and permeability of plastic concrete cutoff walls are affected by lead ion.Plastic concrete composed of cement，bentonite，sand and lead ion solution was taken as the research object to study the influence of different lead ion concentrations and curing ages on the unconfined compressive strength，permeability and physical and chemical properties （pH and conductivity） of plastic concrete.The results showed that at the same curing age，the strength and pH of the plastic concrete decreased with increasing of lead ion concentration，while the conductivity and permeability coefficient of the plastic concrete increased.At the same lead ion concentration，the strength of the plastic concrete increased with the curing age，and the pH，conductivity and permeability coefficient decreased with the curing age.Under different lead ion concentrations and curing age conditions （7d，14d an 28d），the strength and permeability of the concrete showed a good exponential relationship with ratio of pH to conductivity，respectively.

Key words: plastic concrete cut-off wall；lead ion；concrete strength；permeability coefficient；pH；conductivity