Conditions to induce water repellency in soils with dimethyldichlorosilane

Dimethyldichlorosilane has been used as a hydrophobising agent for various applications, one of which is the treatment of soils. In geotechnical engineering, synthetic water-repellent soils can be used in barriers or ground improvement because of their wettability properties. This note examines the effect of dimethyldichlorosilane concentration on the soil type and time-dependent effects by means of contact angles measurements using the sessile drop method. The results reveal that the presence of organic matter, residual water and other non-mineral matter hinders the effectiveness of the treatment. Treated clean soil particle surfaces from crushed rocks achieve an immediate and high degree of water repellency.