CORRELATION OF POLYMER MODIFICATION TO MECHANICAL PROPERTIES OF BINDERS

There is a need to identify a mechanical parameter measured from standardized test that is sensitive to polymer modification of binder. Presence of such parameters would enable an empirical evaluation of the impact of modification of the binder on mixture and eventually on pavement performance. Superpave specifications were primarily designed for neat binders. Researchers have determined that the tests specified in Superpave are not suitable for characterization of polymer modified binders. Asphalts modified with different polymers can behave very differently even when they have the same performance grade, as determined by the Superpave specifications. The objective of this study is to correlate the different quantities of polymer modification to mechanical properties of the binder. In this study, the amount of modification was measured in terms of absorbance as measured by Fourier Transform Infrared Spectrometer. The absorbance was correlated to non-recoverable creep compliance and G*sin(delta) for different types of polymers and at different polymer concentration. The information about the chemical composition of different polymer modified binder and how a particular chemical component modifies or affects a particular mechanical property of the binder, can help the asphalt manufacturer in developing the most cost effective product to meet the specifications.