Preparation and properties of flame-retardant asphalt containing polyurethane and eco-friendly flame retardants

This paper aims to improve the flame-retardant property of asphalt by modifying asphalt with aluminum trihydrate (ATH), montmorillonite (MMT) and layered double hydroxides (LDHs), which are eco-friendly flame retardants, and polyurethane (PU) was used together with flame retardants. The results showed that the combination of PU and flame retardants could significantly improve the high and low temperature performances of asphalt and the flame-retardant property of asphalt. Among the three flame retardants, LDHs with layered structure shows the best flame-retardant performance owing to its behavior of heat absorption and decomposition. Besides, positive synergistic flame-retardant effect between different flame retardants is observed.