Tackiness Properties of Non-Tracking Tack Coats

Non-tracking tacks are introduced to improve the bonding of pavement layers by preventing the tracking problems associated with conventional tacks. However, the evaluation of the non-tracking tacks has not been well-established as compared with the traditional tack coats. The goal of this research was to measure the rheological properties, the bonding potentials and tack properties of non-tracking tack materials. For this purpose, the dynamic shear rheometer (DSR) frequency sweep test was performed on the tack residues for investigating their rheological properties. Also, a pneumatic adhesion tester was used to measure the pull-off strength of the interaction between the residues and aggregate. The DSR tackiness test was conducted to identify the tracking resistance and quantify the tack energy. Three non-tracking tack coats and a traditional tack coat were used. The results of the DSR frequency sweep test showed that the non-tracking tack materials are stiffer than the traditional tack coat. The results from the pull-off testing and the DSR tackiness test demonstrated that the effect of tack type on the bond strength and tackiness was significant. Furthermore, it was shown in the tackiness test that the testing temperature had a major impact on the change of tack energy for the non-tracking tacks.