Impact of aging on asphalt pavement performance, ductility and DSR measurements

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references (leaves 56-58).Issued also on microfiche from Lange Micrographics.In this work, Asphalt binder from Texas, SH 21 was extracted and recovered in different years. This binder was studied and compared with lab-aged binder. This study mainly included dynamic shear rheometer (DSR) measurements and Fourier transform infrared (FTIR). The hardening susceptibility was compared between field binder and binder aged by different lab-aging techniques. The field values were found to match those obtained for lab-aged binder. The comparison between field and lab-aged binder was also established from the perspective of the viscoelastic rheological properties, G' and []'. Data points were plotted on G' vs. G'/[]' map. Both field and lab-aged binder followed the same trend on that map as aging progressed. The study of hardening susceptibility and the rheological properties supports the condition that the aging mechanism is the same in the lab and the field and that the aggregate has almost no effect on the oxidation reaction that occur. The last part in this study was to compare the hardening rate between field and lab-aged binders. This comparison was based on two criteria: the low shear rate limiting viscosity and the DSR function. Using both criteria, one month in the 60 ⁰C environmental room is roughly equivalent to two years in this road. Twenty-four hours of PAV lab aging was found to simulate 2.5 years in the field. No significant difference was found between the top and bottom lift hardening rates. Both lifts seemed to harden at the same rate. Moreover, seal coat asphalt was found to penetrate well into the pavement