Basic physical and mechanical properties of water repellent sand-clay mixed soil

The water repellent soil has many excellent properties. At present, its use is mainly aimed at the water repellent sand. In order to expand the application scope of the water repellent soil, a series tests are carried out. The results show that the loose soil samples of the mixture of the water repellent clay exhibit obvious non-uniformity of water repellency after adsorption stability under isothermal conditions, while the mixture of the water repellent clay and sand exhibits uniformity of water repellency. Two kinds of soils are uniformly repelled after compaction. The position of soil-water characteristic curve of the hydrophilic soil is higher than that of the water repellent soil, but there is no change of matric suction from "attraction" to "exclusion". The cohesion of hydrophilic clay will be reduced after water repellency. Adding hydrophilic sand or water repellent sand does not cause the difference of shear strength. The difference of physical and mechanical properties between the water repellent soil and the hydrophilic soil is mainly due to the adsorption of clay particles and the existence of water repellent clay aggregates. The addition of the water repellent clay and sand greatly expands the application scope of the water repellent soil. The research results may provide the corresponding test basis for the popularization and application of the water repellent soil.