Combustion mechanism of asphalt binder with TG-MS technique based on components separation

To investigate the combustion mechanism of asphalt in this study, asphalt binder was separated into four components, namely, saturate, aromatic, resin, and asphaltene. Thermo-gravimetric analysis coupled with mass spectrometry (TG-MS) was implemented to analyze the combustion behavior of the four components of asphalt in a simulated air environment. The Coats-Redfern Integral Model (CRIM) and Distributed Activation Energy Model (DAEM) were used to calculate the activation energies of the four components during the combustion process, respectively. During the combustion of each component, TG-MS was employed to investigate the weight loss and to identify the products. According to the mass loss rates at different temperature range, the combustion process was divided into several stages at a heating rate of 15 K/min. DAEM was utilized to calculate nine activation energies during the entire combustion process at three heating rates of 10, 15, and 20 K/min, respectively. Comparison of the activation energies obtained with the two methods indicates that the four components have entirely different combustion mechanisms, which demonstrates the importance of the component separation in the investigation of the combustion mechanism of asphalt.