Shear adhesion evaluation of various modified asphalt binders by an innovative testing method

During the last decades, the number of vehicles, as well as the traffic load, has dramatically increased, which has strongly shortened the life of pavements and increased maintenance cost. Most asphalt pavement diseases are resulted from adhesion failure which occurred between asphalt and aggregates. The adhesion properties are crucial factors that influence the capability of asphalt to resist stripping from aggregates. In this paper, shear adhesion test, an innovative test method based on energy theory by using Dynamic Shear Rheometer was introduced and performed to evaluate the effects of various modifiers and additives of different amounts on asphalt shear adhesion property. Meanwhile, binder bond strength (BBS) test was also applied to test the adhesion tension strength of the modified asphalt, and the results from two tests were compared with each other. Furthermore, correlation analysis between findings obtained from shear adhesion test and Hamburg wheel-tracking device (HWTD) test under wet condition was conducted. Shear adhesion test results indicated that SBS, crumb rubber, terminal blend (TB) rubber powder and compound modifier TB rubber powder + SBS improved the shear adhesion property, while polyphosphoric acid (PPA) and ethylene bis-stearamide wax (EBS) had an adverse effect on it. The results acquired from BBS test were roughly consistent with shear adhesion test results when evaluating the variation tendency of adhesion properties of some asphalt which is modified with different amounts of modifiers. The results of the shear adhesion test were in good correlation with the stripping inflection point (SIP) in HWTD test when evaluating the certain kind of asphalt which was modified with different amounts of modifiers, except for some modifiers that would change the asphalt stiffness modulus significantly. (C) 2018 Published by Elsevier Ltd.