The mechanism of flame and smoke retardancy of asphalt mortar containing composite flame retardant material

The study was carried out to analyze the flame and smoke retardancy of asphalt mortars containing composite flame retardant material and the mechanism of which by the help of limit oxygen index, thermogravimetry, difference scanning calorimetry and smoke density test. The results showed that the LOI of asphalt mortar with M-FR can increase by 5.9. Thermogravimetry-Difference Scanning Calorimetry (TG-DSC) analyses illustrated that M-FR can both increase the decomposition temperature and decrease the total decomposition because of the combined effect of MiberIII mineral fiber and mixed flame retardant. Meanwhile, it can play the role of cooling by a great number of endothermic reactions, especially in the temperature range from 400 °C to 500 °C. Max smoke density (MSD), smoke density rating (SDR) were proposed to evaluate the smoke retardancy. The value of MSD and SDR, together with test phenomena, demonstrated that M-FR can reduce the smoke production.

► M-FR can raise LOI of SBS modified asphalt obviously, from 20.1 to 26.0. ► M-FR can both increase the decomposition temperature and decrease the total decomposition due to its flame retardancy. ► Heat release reduce obviously during most of the heating process, especially between 400 °C to 500 °C. ► Smoke test results show that M-FR has good smoke retardancy.