Influence of surface macro-texture and binder dosage on the adhesion between bituminous pavement layers

The effectiveness of an emulsion applied as a tack coat between bituminous pavement layers is usually analyzed according to the dosage and breakage of the emulsion used on site. In this paper different dosages between different bituminous mixtures were analyzed using shear tests, leading to the conclusion that the optimal application range varies from 250 to 500 g/m2. At the same time, the influence of the surface macro-texture of different types of asphalt mixtures on the bond between layers was studied. It was found that the maximum values of shear strength are obtained for a rough texture of 0.17 mm and a dosage of 250 g/m2.

► We study 2 lower layers with 2 upper layers, 6 binder dosages and 2 contact face types.
► We obtain the behavior curves and the best dosages.
► We study 6 lower layers with 2 upper layers and the previous best 4 binder dosages.
► We obtain the behavior curves and the best roughness-dosage correlations.