ABSTRACT
The analysis of the mechanical behaviour of compacted unsaturated clays subjected to cyclic wetting and drying paths has been receiving increasing attention owing to their use as construction material in many Civil and Environmental Engineering applications. Wide experimental evidence shows that in wetting and drying cycles compacted clays can accumulate irreversible volumetric swelling or irreversible volumetric shrinkage depending on stress history and the applied net confinement stress and cyclic suction change (Alonso et al., 2005; Sharma & Wheeler, 2000). Different mechanisms have been suggested in order to explain the observed volumetric behaviour and devise conceptual models reproducing test results. They refer to interactions between multiple levels of material structural arrangements at microscopic scale (Gens & Alonso, 1992; Alonso et al., 1999; Alonso et al., 2005) or to hydraulic hysteresis and void ratio dependence of material retention curves (Buisson & Wheeler, 2000; Vaunat et al., 2000).
