Long-term and immediate effects of freeze–thaw cycles on the resilient modulus of treated expansive subgrades
Ahmed M. Al-Mahbashi, Mosleh A. Al‐Shamrani
Abstract
This study aims to investigate the long-term and immediate effects of freeze-thaw (FT) cycles on the resilient modulus (MR) of two different expansive subgrades before and after lime-treatment. The immediate effects were examined by performing MR test (using triaxial dynamic-system) for specimens immediately after applying successive FT cycles. For assessment of long-term effects, the specimens were subjected to 15 FT cycles and then thawing in a humidity room for different recovery periods up to 250 days before commencing MR tests. The results indicated a reduction in MR by about three times due to FT cycles regardless of lime-treatment. This reduction mostly took place after first FT cycle and showed a dependency on FT cycle number. On long-term performance, the reduction was not entirely recovered for all soils, and reducing the designed values of MR is recommended when pavement subgrades are to be subjected to FT cycles even once a year.