Effect of flame retardant on the performance of asphalt and asphalt mixture

Asphalt is a combustible material. To prevent fire and other major accidents, it is necessary to add flame retardant to the long tunnel asphalt pavement. However, there are many kinds of flame retardants in the market, and the effect of adding flame retardants to asphalt pavement on its performance remains to be studied. The effects of two different flame retardants on the properties of asphalt and asphalt mixture were studied. The results showed that the two flame retardants could improve the softening point, rut factor and limit oxygen index of asphalt. What's more, the ductility and the anti-fatigue performance of asphalt would be reduced by the flame retardants. Along with the addition of flame retardant, the high-temperature stability of asphalt mixture was improved, while the low-temperature crack resistance and water stability were decreased. FR-4 flame retardant has a greater influence on the high-temperature performance of asphalt and asphalt mixture, but the low-temperature performance will be significantly reduced. And the improvement of flame retardant performance is not as good as that of flame retardant ZL-1.