Hysteresis of Soil Water Retention Curve of Water Repellent Soils by Continuous Pressurization Method

Abstract

The water retention tests in this study were conducted using wettable and water repellent soils to investigate its water retention characteristics. For this, a newly established water retention testing system which uses continuous pressurization method was utilized, and the water repellent sand was artificially prepared by the silanization process. As a result, it was confirmed that the testing time for the drying and wetting processes in the soil water characteristic curve was remarkably shortened. The air entry value of the water repellent soil is similar to that of the wettable soil, while the water entry value and water infiltration value of the water repellent soil are smaller than the wettable soil. Even with a limited data, this indicates that the effect of the repellent state on soils has a larger hysteretic behavior than the wettable state on soils due to material characteristics.