Development of a Suitable Procedure for Simulating Aging Effects of Hot-Mixing onModified Asphalts for Use in Superpave Binder Specifications

摘要

Prior studies have shown that asphalts modified with coarse crumb rubber and SBRtended to spill out from the bottles during the Rolling Thin Film Oven Test (RTFOT) process. When the standard Thin Film Oven Test (TFOT) was used, a thin skin tended to form on the surface of some modified asphalt samples, which reduced the homogeneity and the aging of the samples. In this study, the rotavapor apparatus, which was originally used for recovery of asphalt from solution (ASTM D5404), was modified to work as an aging device for asphalt, and evaluated for its suitability as a replacement for the standard RTFOT procedure for simulation of short-term aging of both pure asphalts and modified asphalts. The modified rotavapor aging procedure was found to be a versatile and effective method for aging of pure asphalts and modified asphalts. It has advantages over the standard RTFOT and TOFT procedures in that (1) there was no spillage and skin formation problem, (2) a large sample size can be used, and (3) different levels of aging of the asphalt samples can be achieved. It is recommended that the possible implementation of this aging method for simulation of short-term aging in place of the RTFOT process and long-term aging in place of the RTFOT + PAV process be pursued.