Reliable Estimation of Binder Properties Using the Large Molecular Size (%) from Asphalt Mixtures

Abstract

In general, the binder properties of asphalt mixture can be measured only when the binder is recovered from the mixture. However, this study showed the method of estimating the binder property reliably using gel-permeation chromatograph (GPC) technique without binder recovery from loose mixes, compacted specimens or field cores. The large molecular size (LMS) of asphalt can be measured by the GPC test directly from the asphalt mixture sample and then used to estimate necessary property of the binder. To show its applicability, this study estimated the service life plus four properties [the stiffness (G*/sinδ), absolute viscosity (AVS), penetration (PEN), and dynamic shear rheometer (DSR) pass/fail (P/F) temperature] based on the LMS. Many cores taken from 6 sites in Korean Expressways and a lab-prepared mixture were used. The regression analyses found that the AVS and P/F temperature showed very high correlations (R2 > 0.98) with LMS. The G*/sinδ, PEN, and service life had high correlations with LMS showing R2≒0.93, 0.92, and 0.88, respectively. Therefore, LMS is a good prediction tool for binder’s physical properties. Therefore, it is possible to say that the LMS will be a reliable prediction medium of physical properties of asphalt binder in the mix.