Volume changes and consolidation of expansive subgrades under short- and long-term effects of freeze–thaw cycles

Abstract

ABSTRACT Pavements and light structures constructed on expansive subgrade layers have experienced severe damage due to volume changes. These layers have been exposed to climatic changes such as freeze–thaw (FT) cycles. Accurate estimation of design parameters regarding heave/settlement is essential for sustainable performance. This work study the instantaneous and long-term effects of successive FT-cycles on the volume stability, swelling, and compressibility characteristics of natural and lime-treated expansive subgrades. Volume changes were traced during successive 15FT cycles. Swelling and consolidation characteristics were studied immediately after FT-cycles. The long-term effect of FT was tested at different recovery periods around year. FT-cycles significantly affects volume changes and compressibility, this effect is proportional to soil type and limited up to a certain number of FT-cycles. During the long-term recovery, a considerable part of underwent deformation is a permanent and not recovered, even after year the soil still memorizes this effect. Due to the propagated cracks, the plastic deformation increased with increase in FT-cycles.