Influence of interface properties on heavy weight deflectometer test results

Pavement layer interfaces have a major influence on pavement structure service life and bearing capacity. This study aims at understanding how interfaces behaviour can affect the pavement response in the frame of airfield pavement assessment with the Heavy Weight Deflectometer device. Based on laboratory viscoelastic characterisation of an interface, numerical simulations allow comparing various interface conditions: fully bonded, perfectly sliding and with elastic or viscoelastic stiffnesses. It is shown that interface viscoelasticity participates to the pavement surface deflection response. This contribution is significantly affected by pavement temperature and load frequency content. Computations also demonstrate that, in the studied case, interface viscoelasticity does not question current rational pavement design methods for new roads, whose behaviour stays close to the ‘fully bonded’ case.