Effect of Localized Friction Changes in the Layer Interface on Formation of Y-Cracks in CRCPs

When transverse cracks meander there is a high possibility for transverse cracks to meet at a point and connect to another transverse crack, creating a Y-crack. Y-cracks have been blamed for being the origin of punchouts and spallings in Continuously Reinforced Concrete Pavements (CRCP). When the direction of maximum principal stress changes, it could cause a change in the crack direction, potentially forming a Y-crack. In this study, finite element model of CRCP using typical Oklahoma CRCP pavement conditions and design was assembled. The model included the concrete pavement, asphalt concrete subbase, and soil subgrade. A localized change in friction between the concrete and supporting layers was modeled to determine how subbase construction uniformity could affect y-cracking. The effect of areas of changed friction on the direction of principal stress was simulated by considering a patch at the pavement-subbase interaction. Investigated factors related to this patch were friction coefficient between patch and subbase and patch size. A change in the friction had a large effect on the stress magnitude and direction of principal stress, leading to Y-cracks.