Abstract: In order to explore the change laws of the flame retardant and smoke suppression performance of asphalt after aging under different conditions, a rotating film oven (RTFOT) was used to perform 85 min short-term aging, 270 min long-term aging and damp heat aging on the base asphalt. Limiting oxygen index test (LOI) and cone calorimetry test were used to study the fire safety performance of aged asphalt, combining with infrared spectroscopy (FTIR) and thermogravimetric-mass spectrometry (TG-MS) was used to analyze the change laws of asphalt components and gaseous product release. The test results show that the base asphalt have lightweight component reduction and heavy component increase after thermal oxidative aging, which leads to an increase in the LOI, while the hot and humid aged asphalt decreases the LOI of asphalt due to the partial pressure of water vapor. In terms of heat release, the peak heat release rate of asphalt combustion decreases after thermal oxygen aging, and the peak corresponding time advances, and the effective heat combustion decreases; while the heat release rate remains basically unchanged after damp heat aging. In terms of gaseous products release, after thermal oxidative aging, the release of soot, CO, and CO2 from asphalt combustion is lower, and the release of SO2 increases; after damp heat aging, the release of soot, CO and CO2 does not change much, but the release of SO2 increases significantly.

Key words: asphalt, thermal oxygen aging, damp heat aging, flame retardant and smoke suppression, gaseous products release characteristics