Measuring Surface Tackiness of Modified Asphalt Binders and Emulsion Residues using a Dynamic Shear Rheometer

摘要

Non-tracking tack coats, primes and fog seals have been developed to minimize pick up of the binder by the tires of traffic or construction vehicles. The binders can be hot-applied but more often are applied as emulsion. The properties of the emulsion residues for trackless recipes are typically characterized by penetration and softening point in state DOT specifications. These traditional measurements may not fully predict the performance of trackless products in the field, especially at extremes of road surface temperature and with polymer-modified or unconventional binders. A simple method to compare the tackiness of different binders would be useful in designing these non-tracking materials and has the potential to predict the maximum road temperatures for which a particular formulation is suited. We previously reported our application of the Dynamic Shear Rheometer (DSR) to measure the “tackiness” of asphalt binders. In this paper we describe improvements to the DSR method, and report on the tackiness of modified and unmodified asphalt binders and emulsion residues covering a range of softening points and penetrations. A proposed ASTM standard procedure has been developed from this work, including a potential test specification pass-fail parameter.