Experimental research of swelling behaviors with initial water content and matric suction of bentonite–sand mixtures

In order to discuss the relationship among the initial water content, matric suction and swelling behaviors, both swelling behaviors and matric suction were measured in laboratory test. Results of swelling tests indicated that with the increase of initial water content, the maximum swelling pressure was reduced in a lower water content range and almost constant in the higher water content range. The maximum swelling strain was linearly reduced with the increase of initial water content. The influence of initial water content on the swelling behaviors was more obvious for specimens with higher initial dry density or lower sand content ratio. Relationship between matric suction and initial water content ratio was obtained, and results showed that matric suction decreased with the increase of water content for specimens with the same dry density, which was more obvious when the water content was less than 25%. The extent of the impact by water content, however, was found to be dependent upon the characterist...