老化对基质沥青阻燃抑烟性能的影响

为探究不同条件老化后沥青阻燃抑烟性能的变化规律，采用旋转薄膜烘箱（RTFOT）对基质沥青进行85 min短期老化、270 min长期老化以及湿热老化。利用氧指数试验（LOI）和锥形量热试验研究老化沥青火灾安全性能，同时结合红外光谱分析技术（FTIR）以及热重-质谱联用技术(TG-MS)分析沥青（BA）成分与气态产物释放特性的变化规律。试验结果表明：基质沥青在经历热氧老化后轻质组分减少，重质组分增加，导致氧指数提升。而湿热老化中由于水蒸气分压力的作用使沥青氧指数略有下降。在热释放方面，热氧老化后沥青燃烧热释放速率峰值下降，峰值对应时间提前，有效燃烧热降低；而湿热老化后热释放速率基本不变。在烟气释放方面，热氧老化后沥青燃烧的炭烟、CO、CO2释放量更低，SO2释放量增加；湿热老化后炭烟、CO、CO2释放量变化不大，而SO2释放量明显增多。

Effect of aging on the flame retardant and smoke suppression performance of base asphalt

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.