Rapid determination of styrene-butadiene-styrene (SBS) content in modified asphalt based on Fourier transform infrared (FTIR) spectrometer and linear regression analysis

Abstract

A rapid method predicting SBS content in SBS modified asphalt was proposed. Portable Fourier transform infrared (FTIR) spectrometer was used to obtain infrared spectra of original asphalt, SBS modifier, and SBS modified asphalt. Two test methods and two software programs were applied for processing data in infrared spectra. Absorption peak at the wavenumber of 966 cm−1 was selected as the characteristic peak of the SBS modified asphalt, and absorption peaks at 1377 cm−1 and 813 cm−1 were used as characteristic peaks of original asphalt. Linear regression was conducted to establish the relationship between SBS content and characteristic peaks parameters. Finally, a prediction method was developed and its accuracy, repeatability, and applicability were verified. Results show that potassium bromide pellet method is better for FTIR testing. Characteristic peak height (or area) ratio of SBS and original asphalt linearly changed with SBS content. Peak area ratio has better correlation with SBS content.