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Characterization of Pavement Layer Interfaces.

The aim of this research was to derive constitutive models for the interfaces of flexible pavement layers and to determine the effects of interface condition on pavement performance. A simple constitutive model was derived for the asphalt layer interfaces using data provided by laboratory direct shear tests at several normal load levels. In the model the shear displacement is proportional to the shear stress until the shear strength of the interface is reached. Field shear tests at several levels of normal load were used to study the bond between asphalt surface layers and granular or soil-cement bases. The interface constitutive models were integrated into the ABAQUS finite element model to prove the significant impact of the interface condition on pavement life.