Using a modified asphalt bond strength test to investigate the properties of asphalt binders with poly ethylene wax-based warm mix asphalt additive

This paper presents a feasibility of a modified Asphalt Bond Strength (ABS) test method for use with a new adhesion testing device with three different pullout stubs and its application for evaluating Polyethylene (PE) wax-based Warm Mix Asphalt (WMA) additive. Four different asphalt binders were used to evaluate the feasibility of applying the existing AASHTO ABS test method using a new ASTM-certified adhesion testing device and three different pullout stubs. The modified ABS test method was used to evaluate the loss of adhesion and cohesion in asphalt bond strength due to moisture-induced damage. The paper also discusses rheological properties of extracted asphalt binders from three different test sections in Minnesota, Ohio and Iowa constructed using PE wax-based WMA additive and different amounts of Reclaimed Asphalt Pavement (RAP) materials. Based on the modified ABS test results using the new adhesion testing device, it was found that the proposed pullout stub with 0.0 mm thickness (no edge) exhibited consistent results. Based on the results from extracted asphalt performance grading and the multiple stress creep recovery (MSCR) test, it was found that the PE wax-based WMA additive, which was specially designed for asphalt mixtures with a high RAP content, significantly improved the rheological properties of aged asphalt binders from RAP materials.