Experimental investigation of related properties of asphalt binders containing various flame retardants

The improved flame retardancy of asphalt binders containing various kinds of flame retardants including antimony trioxide, decabromodiphenyl ether (EBPED), aluminium trihydroxide (ATH) and zinc borate (ZB) under different additive concentrations was investigated by limited oxygen index (LOI) and differential scanning calorimetry (DSC) test. To assess the effects of the type and concentration of the flame retardants on rheological properties of asphalt binders, the softening point, penetration, ductility, storage stability and viscosity were tested. The thin film oven test (TFOT) was used to investigate the effect of short-term oxidation on flame-resistant asphalt binders. Experimental results indicated that all of selected flame retardants had a relatively small effect of rheological properties of the asphalt binders, but a great effect on flame retardancy. Asphalt binder with LOI of 25.9 was obtained by adding 6 wt% mixed flame retardants of EBPED: antimony trioxide: ZB=3:1:1 by mass. Asphalt binder was transformed from inflammable materials into flame retardant materials. Therefore, the asphalt binder with both good flame retardancy and rheological properties is a novel road functional material to meet two respects' demands as flame retardant materials and road materials at the same time.