An FT-IRS Approach for the Evaluation of SBS Degradation in SBS Modified Asphalt Binder

摘要

In the previous study, a hand held Fourier transform infrared spectrometer (FT-IRS) was used to predict the SBS content (%) in the Styrene-Butadiene-Styrene (SBS) modified asphalt binder. Peak height at 965 cm"1 of the FT-IR spectrum which indicates polybutadiene functional group was used to quantify the SBS content (%) in the modified asphalt binder. A universal curve was developed which predicted SBS content (%) in the laboratory prepared samples and in the field measurement within a percentage error of 0%-5% and 5%, respectively. In this study, the SBS content (%) of the SBS modified asphalt (SBSMA) binders was evaluated before and after aging. Different SBS modified PG 64-28, PG 64-34, PG 70-22, PG 70-28, and PG 76-22 binders were collected from different sources (NV, MS, and WA). These binders were RTFO (rolling thin film oven) and PAV (pressure aging vessel) aged in the laboratory. Using the equation, it was found that SBS content (%) was reduced by about 6-14% after RTFO aging, and 15-30% after PAV aging. Raising of carbonyl (C=O) and sulfoxide (S=O) content was also observed after RTFO and PAV aging, which indicated the oxidation in the SBSMA binder. Besides, the novel DSR (dynamic shear rheometer)-based extensional deformation test results showed similar reduction after aging which indicated the efficiency, viability, and potential of using FT-IRS in laboratory conditions for the evaluation of SBS degradation.