EVALUATION OF TACK COAT ADHESION BY SHEAR TEST USING CYLINDRICAL SPECIMENS

Abstract

 In recent years, the importance of the issue of age-related damage and long-term durability of asphalt pavements has been increased. In order to extend the service life of asphalt pavements, the development of tack coat with long-term adhesion is being promoted because it is expected that the long-lasting interlayer adhesion of asphalt pavements will greatly extend the service life of asphalt pavements. In Japan, the adhesion of tack coat is mainly evaluated by tensile adhesion test, but sometimes it is not possible to evaluate the adhesion properly because of the internal failure of asphalt mixture especially at high tempetatare or using modified asphalt emulsion with strong bonding property. On the other hand, overseas, tack coat is evaluated by a shear test using a test fixture designed to suppress internal failure of the asphalt mixture. Therefore, the applicability of the cylindrical shear test to the evaluation of tack coat adhesion was examined in this study. The results suggest that the cylindrical shear test can suppress the internal failure of asphalt mixtures and can appropriately evaluate the adhesive properties of tack coat.