Abstract

The contamination of soil and groundwater is a widespread issue that can adversely affect human health and ecosystems. The containment approach using cut-off walls is one of the most commonly used land remediation technologies. Despite the widespread application of cement-bentonite slurry trench cut-off walls and soil mix technology constructed cut-off walls, the materials deteriorate under mechanical, chemical, and environmental stresses. The damage of cut-off walls can lead to the problems related to the undermined mechanical and transport properties, impacting their serviceability and reliability and in some cases leading to the undetected physical breach of the wall. Developing crack-resistant and self-healing cement-bentonite and soil mix materials could provide more resilient, sustainable, and reliable cut-off walls with significantly enhanced durability, reduced maintenance costs, enhanced safety, and protection against sudden or undetected failure. This PhD research investigates the development of crack-resistant and self-healing cementitious cut-off wall materials incorporating polymers and minerals. The overall performance of four additives, including superabsorbent polymers (SAPs), oil sorbent polymers, reactive magnesia (MgO) and microencapsulated sodium silicate (Na₂SiO₃) in two cut-off wall materials (cement-bentonite slurry and soil mix cut-off wall materials) is the interest of this study.