Combined effects of temperature and moisture content on soil suction of compacted bentonite

Based on experimental determination of soil suctions of two clayey soils, this study investigated the combined effects of temperature and moisture content on soil suction. First, two clayey soils were statically compacted at target moisture contents ranging from 5% to 20%, such that a broad spectrum of compaction conditions can be evaluated. Then, filter paper method and thermocouple psychrometer were adopted to measure soil suction, including total and matric suctions, at temperatures ranging from 10°C to 60°C. It was found that soil suctions of expansive soils vary with compaction parameters such as compaction moisture content and compaction effort, and that temperature is influential on soil suction also. As moisture content increases, the effects of compaction effort and temperature on suction become less significant. Formulations developed using multiple regression were established for predicting the soil suction of as-compacted expansive soils.