Thermal, chemical and imaging analysis of Polyurethane / Cecabase modified bitumen

Abstract

In this study, a 60/70 penetration grade bitumen was modified with polyurethane (PU) added with a Warm Mix Asphalt (WMA) additive, i.e. Cecabase, in the amount of 0.5 wt % with respect to bitumen. The thermal characterization was done using the Differential Scanning Calorimetry (DSC) while the chemical analysis was done using Fourier Transform Infrared (FTIR). Raman Spectroscopy was used to characterize the asphaltic materials in the bitumen, namely the D (Defect) and G (Graphite) bands. Test results showed that adding PU and Cecabase to the bitumen slightly shifted the Tg and Tm peaks of the thermal behaviour. The result of FTIR showed that there was no shift in the carbonyl and sulfoxide peaks, which indicate that no chemical interaction occurred in the unmodified and modified bitumen. Furthermore, the Raman Spectroscopy investigation revealed that PU and Cecabase reduced the wax content and decreased the bee-structure of the bitumen samples. However, the order structures of unmodified and modified bitumen were still within the boundary limit of the D and G bands of the Raman spectra. In conclusion, the use of PU and Cecabase as bitumen modifier are promising for alternative source for bitumen.