Flame retardancy, thermal, and mechanical properties of mixed flame retardant modified epoxy asphalt binders

The epoxy asphalt (EA) binder has been widely used for the pavement on the steel plate deck and in tunnels. In this study, horizontal burning and limiting oxygen index (LOI) were conducted to evaluate the effects of mixed decabrombromodiphenyl ethane (DBDPE) and antimony trioxide (Sb2O3) on flame retardancy for epoxy asphalt binder. The influence of DBDPE/Sb2O3 on the rotational viscosity, the thermal and mechanical properties of epoxy asphalt binder was evaluated by thermogravimetric (TG) analysis, differential scanning calorimetry (DSC), and tensile test. The addition of DBDPE/Sb2O3 reduces the horizontal burning classification of epoxy asphalt binder from FH-2 to FH-1, and the LOI values of EAs is also significantly increased. The addition of flame retardants has no significant effect on the rotational viscosity of EA in the initial stage of cure reaction. TG results show that the presence of DBDPE/Sb2O3 improves the thermal stability of the epoxy asphalt binder. The addition of DBDPE/Sb2O3 has little effect on the tensile strength of the epoxy asphalt binder. However, the elongation at break of flame-retarded EAs is lower than that of the neat EA.