Experimental characterisation of clay-sand mixtures treated with lime

Lime stabilisation is a process which chemically improves numerous characteristics of the soils, among which aspects, the mechanical properties increase are the most noticeable. This paper investigates the lime treatment of mixtures of sand and bentonite at different proportions. Three physical characteristics are measured at different curing times: the mechanical strength is deduced from unconfined compressive strength (UCS); the chemical reaction is evaluated based on the lime consumption (LC) and the electrical properties are obtained from electrical resistivity (ER). Results show that all three physical characteristics increase with curing time and that the optimal UCS appears at mixtures with low bentonite content (i.e. 10-15% bentonite). LC curves show that the kinetics of the lime reaction is also slower at these low bentonite contents. Finally, the ER curves show similar patterns for all mixtures and are closely related to the LC.