Abstract
Applying organo-silanes (OS) as water-repellent additives can enhance soil properties, crucial for use as moisture barriers in infrastructures like roads, landfills, and tunnels. This study used four soil samples and glass beads, treated with three OS products at dosages from 1:1 to 1:1000. Laboratory tests included contact angle, water drop penetration, and breakthrough pressure on 216 samples. Results showed increased hydrophobicity with higher OS dosages, with contact angles over 110 degrees and Water Drop Penetration Test times above 3600s. However, effectiveness plateaued at certain dosages, indicated by electrical conductivity and pH changes. The primary factors (94.6% influence) were soil type, OS product, dosage, and drying condition, while reaction time, and leaching/washing had a minor impact (5.4%). Treated soils could sustain a hydrostatic head of up to 17 kPa. These insights aid in optimizing water-repellency treatments for soil performance and infrastructure durability in geotechnical applications.