Interface debonding behaviour
Résumé
The performance and durability of multi-layered pavements strongly depend on interlayer bonding between layers, especially for pavements with a thin or ultra-thin surface course. These pavements, comprised of several differing material layers, are often subjected to premature distresses (corrugation, peeling, slippage or fatigue cracking, etc.) caused by poor interface bonding. This chapter summarizes the different bond characterization tests available around the world (mostly in the laboratory) available to characterize the bond between pavement layers. Many of the tests can be performed on specimens prepared in the laboratory or on cores or slabs obtained from the pavement. Mostly, 'pure' fracture mode test methods (opening mode I or in-plane, shear mode II or out-of-plane, shear mode III) are currently used worldwide for determining the interlayer bond of pavement layers. Most of the mixed-mode test methods (mainly for the combination of Modes I and II) were developed by a few research teams and there are therefore no standard tests. Although tack coat type and content are the main parameters studied by researchers and engineers, surface roughness, moisture, freezing, and presence of dust or debris on the interface are additional parameters that may decrease bonding performance.