Characterising emulsion effects on aged asphalt concrete surfaces using Bending Beam Rheometer mixture beams

摘要

A function of asphalt emulsions is often to rejuvenate the surface of an aged asphalt concrete roadway. However, it is unclear as to the effectiveness of different types of asphalt emulsions, as most current testing is empirical and does not give an indication of field performance. Using asphalt concrete beams from the surface of a roadway in the Bending Beam Rheometer is a new approach that may give an indication of an asphalt emulsion's ability to decrease the stiffness. Seven emulsions at three application rates on two roadways were examined to identify the effect of emulsion on the stiffness and m-value of asphalt concrete. The addition of asphalt emulsion generally decreased the stiffness of the aged pavement samples; however, results were fairly erratic and inconsistent compared to change in m-value. The addition of emulsion consistently increased the m-value. Requiring an aged asphalt m-value increase of 0.05-0.06 was suggested as an initial value for consideration within specifications for projects where rejuvenation is a first-order concern.