Effect evaluation of freeze-thaw on resilient modulus of unsaturated granular base course material in pavement

This study examines the effects of freeze-thaw and water content on the resilient deformation characteristics of subbase course materials to evaluate the mechanical behavior of granular base in cold regions. A series of resilient modulus tests on subbase course materials under various water contents were conducted using a newly developed test apparatus. Besides, the test results were compared with the results of freeze-thaw CBR tests and the long-term field measurement at a model pavement structure including FWD tests. As the results, it was revealed that the resilient deformation characteristics of unbound granular base materials (UGBMs) deteriorate due to freeze-thaw and increment of the water content in thawing season. This indicates that the freeze-thaw of granular base has a strong influence on the fatigue life of pavement structures