Cement bentonite cutoff walls for polluted sites

Abstract

Cement-bentonite (CB) cutoff walls have long been used to control ground water flow and contaminant migration at polluted sites. Hydraulic conductivity and unconfined compressive strength are two short-term properties often used by industry and owners in CB specification and are important parameters discussed in this paper. For polluted sites, long-term compatibility is also an important issue. These properties are coupled to a number of external factors including the mix design, construction sequence, presence/absence of contaminants at the site. Additional short-term properties for engineering assessment include the stressstrain characteristics in both drained and undrained shear in both with and without confinement as well as one-dimensional consolidation properties. Long term CB properties are affected by aging, reaction chemistry, drying, in situ stress state, and interaction with the polluted environment. © 2013 Taylor & Francis Group.