INVESTIGATION OF BONDING, BETWEEN ASPHALT LAYERS ON ROAD CONSTRUCTION

Bonding of asphalt layers on road construction is usually examined wit h the pull-off test, measuring the adhesive power. This value however, is not appropriate to characterize the fracture-mechanical behavior o f layer bondings and is thus inappropriate to be introduced into fract ure-mechanical finite-element simulations. Therefore a simple procedur e for measuring the fracture-mechanical behavior of layer bondings has been developed in this study. Cubic or cylindrical specimens (with th eir interface in their middle and a starter notch in the interface) ar e split under stable crack growth conditions. During testing, the comp lete load-displacement curve is determined until final fracturing of t he bonding takes place. The load-displacement curve characterizes the mechanical behavior of the material bonding in the crack opening mode and is an important basis for a numerical treatment of interface probl ems. Results obtained with this new measuring procedure are presented and discussed. As an example, propagation of reflection cracks in a pa vement consisting of-two asphalt layers is simulated for single loadin g of the pavement.