HP-GPC Approach to Evaluating Laboratory Prepared Long-Term Aged Rubberized Asphalt Binders

The high pressure-gel permeation chromatographic (HP-GPC) testing was adopted to determine the molecular size distribution (MSD) of asphalt binders. The percentages of large, medium and small molecular sizes of asphalt binders are able to help the researcher and engineer determine the aging characteristics of asphalt binder. The objective of this research was to investigate the aging behavior of the rubberized asphalt binders as well as the virgin binder and the binder using 3% Styrene-butadiene-styrene (SBS) polymer after a long-term aging through the laboratory HP-GPC testing approach. The experimental design included the uses of three binder sources, three binder grades and three aging levels, i. e., virgin, rolling thin film oven and pressure aging vessel that included three testing temperatures (85, 100 and 110°C) and three aging durations (15, 20, and 40 hours). The results indicated that the HP-GPC approach can effectively describe the aging status of asphalt binders; the use of crumb rubber could improve the aging resistance of the asphalt binder; in addition, the PG 64-22 binder mixed with 10% crumb rubber generally showed the similar aging properties as of PG 76-22 using 3% SBS polymer after a long-term aging process in this study.