• Masrouri, Farimah
• Nowamooz, Hossein

Abstract

International audience ; The soilfabric plays an important role in complex hydromechanical behaviour of the expansive soils. This article addresses the influence of the wetting and drying paths on the soilfabric of compacted bentonite and silt mixtures at two different initial dry densities corresponding to loose and dense states. To obtain the hydric response of the soil, two suction imposition techniques were used: osmotic technique for the suction range less than 8.5 MPa and the vapour equilibrium or the salt solution technique for the suction range between 8.5 and 287.9 MPa. Additionally, the soilfabric analysis was performed using mercury intrusion porosimetry (MIP) and nitrogen gas adsorption (BET) techniques. The dense samples produced cumulative swelling strains during the suctioncycles, while shrinkage was observed for the loose samples. The suctioncycles induced an equilibrium state indicative of the elastic behaviour of the samples. The soilfabric analysis showed that regardless of the soil's initial state (loose or dense), the samples obtained the same soilfabric at the equilibrium state. The experimental results illustrated also the existence of an elastic void ratio (e0el) where the compactedsoils at this state present an elastic hydric behaviour during the successive suctioncycles.

Topics

• laser emission spectroscopy
• Nitrogen
• void
• drying
• porosimetry
• Mercury