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

Development of an estimative model for the optimal tack coat dosage based on aggregate gradation of hot mix asphalt pavements

“…[7] and Raposeiras et al [8], who obtained the least effective dosages below 300 g/m2 of residual binder and the best results from 300 to 450 g/m2.…”

“…Another important factor is the surface finish, which was evaluated by Tashman et al [11], who observed greatest sample strength with milled surfaces, where the tack coat has a minimal influence. Raposeiras et al [8] evaluated the role of the surface layer macro-texture to where the coat was applied. This parameter is defined as the degree of surface deviations present in the longitudinal direction range of 0.5 to 50 mm and peak amplitude of 0.2 to 10 mm, in relation to a flat surface [17].…”

“…These parameters include the type of emulsion used, dosage applied, binder-aggregate adhesion in the interface or setting time of the emulsion [4,5,6,7,8,9,10,11,12]. Some authors have further evaluated the importance of surface conditions on pavements, such as the degree of surface dust particles or the level of surface texture, which highly influences the final bond degree between layers, in some cases more than the characteristics of the emulsion [2,8,11,13]. Raposeiras et al [8] indicate that the surface macro-texture of the layer influences slippage resistance between pavement layers bonded by a tack coat.…”

“…Some authors have further evaluated the importance of surface conditions on pavements, such as the degree of surface dust particles or the level of surface texture, which highly influences the final bond degree between layers, in some cases more than the characteristics of the emulsion [2,8,11,13]. Raposeiras et al [8] indicate that the surface macro-texture of the layer influences slippage resistance between pavement layers bonded by a tack coat. This knowledge is fundamental when selecting an adequate emulsion dosage for the coat.…”

“…A model using experimental data from shear strength tests was adjusted, which allows us to estimate the optimal magnitude of slip resistance on layer interfaces before the tack coat is applied. This is analysed according to the aggregate gradation of the asphalt layer to which the tack coat is applied, which is directly related to the macro-texture degree of the asphalt layer [8].…”