Characterising the bonding between asphalt ultra-thin layers applying a new cyclic shear test

Abstract

Bonding between layers is a critical aspect in the durability and performance of asphalt pavements. The life of the pavement can be significantly reduced due to poor bonding between bituminous mix layers. For this reason, the analysis of the link between these layers is fundamental. Thus, the aim of this work is to analyse the bonding between layers, provided by different types of emulsions, when one of the layers is thin. The bond between these layers was studied by means of a monotonic shear adhesion test, with an analysis of the effect of the dosage, the temperature and ageing, and by means of a new cyclic shear test especially developed in this work. The results obtained show the great influence of temperature on the shear stress for any of the emulsions used, which increases as the temperature decreases, and how the differences between the three emulsions are reduced after ageing. As regards fatigue strength, the choice of the emulsion that will withstand a greater number of cycles will depend on the stresses that occur at the interface.