Pyrolysis characteristics analysis of cold mix asphalt mixture based on TG-FTIR-GC/MS

Abstract

This study aims at the pyrolytic behavior of cold mix asphalt mixture (CMAM), and addressing the existing knowledge gap related to their thermal stability in fire-risk scenarios. Based on a combined TG-FTIR-GC/MS approach, the pyrolysis behavior of CMAM was analyzed at heating rates of 10, 20, and 30 K·min−1. Pyrolysis kinetic parameters were calculated and the reaction mechanism function was determined employing both linear and nonlinear methods. The results show that the main phase of pyrolysis weight loss in CMAM occurs within the temperature range of 600–860 ℃, implying weight loss ranging from 41.4% to 41.7%. Activation energy values, determined by the Flynn Wall Ozawa (FWO) and Kissinger Akahira Sunose (KAS) methods, exhibited substantial similarity. Furthermore, the Vyazovkin method was used to confirm the activation energy value. The main peak activation energy, calculated through the Kissinger method, was 172.4473 kJ·mol−1. Moreover, the Coats Redfern (CR) method was used to determine the pyrolysis mechanism model of CMAM as R3. Analysis via infrared spectroscopy indicated that the main small molecule product is CO2. Experimental data from gas mass spectrometry suggested the potential generation of 9 products. This study provided significant reference for a deeper comprehension of the thermal stability and fire safety characteristic of CMAM.