ABSTRACT
Abstract The purpose of stress-relieving systems is a reduction of the shear stiffness of the overlay / existing pavement interface. These systems should enable the occurrence of considerable movements of the old layers without causing high stresses in the overlay. Stress-relieving systems mainly consist of a thick layer of (modified) bitumen sprayed onto the old surface before the overlay mix is layed down. A constitutive model is presented, capable of showing the effect of thickness and material properties of the applied bitumen as well as pavement surface geometry, on the stiffness value which can be "offered" by a stress-relieving system. A thermal overlay design example showed that, under specific circumstances and within the scope of the one-dimensional bar model utilized, a reduction of the interface shear stiffness by a factor 10 implies a factor 2 increase in lifetime of a 140 mm thick bituminous surfacing which is placed on top of a concrete slab. Keywords: Bitumen, Crack Opening, Interface Shear, Stress-Relief, Temperature, Textile, Thermal Overlay Design, Transverse Cracking.
