| Four different samples of asphalt cement (non-modified asphalt, and asphalt binders modified with 1%, 3%, and 5%) were obtained from four major sources of asphalt refineries in the United States. Three different types of procedures were used to characterize the asphalt binder and to calculate the amount of Styrene-Butadiene-Styrene (SBS) present in the asphalt binder. These methods include asphalt binder fractionation, Fourier Transform Infra-red Spectroscopy (FTIR) analysis, and Spectral ID hit quality index (HQI) calculations.; The asphalt binder fractionation gave an indication that the SBS copolymer was present in the aromatic fraction. The FTIR showed characteristic frequencies of the SBS polymer at the 650–1100 cm−1 frequency range and were used to calculate the SBS content in the asphalt binder. The Spectral ID calculations provided the HQI at the 650–1100 cm −1 range. The HQI number increased respectively to the increase of the SBS polymer in the asphalt binder. |
