Cut-off walls are underground vertical barriers with extremely low permeability employed for soil waterproofing and to seal off water seepage from landfills and contaminated sites. In the remediation of soils, HDPE liners can be inserted in the cut-off walls to provide 100% sealing. Cut-off walls are normally constructed with mechanical grabs and self-hardening mud used as drilling mud during digging and as a low-permeability barrier after setting. Other techniques are also employed, i.e. Cutter Soil Mixing (CSM), in which the soil is loosened and broken down by cutter wheels then mixed in-situ with self-hardening slurry to form a soil-slurry mortar. Our products are employed in this field for major works. In addition to assisting our customers in selecting products and blend formulations that best meet spec requirements, our Technical Service carries out all pre-qualification tests, including resistance and permeability testing with triaxial cells, and provides expert assistance during project design and execution phases.