Effects of aging on the properties of modified asphalt binder with flame retardants

Effects of aging on the properties of asphalt binders modified by incorporating Styrene–Butadiene–Styrene (SBS) and flame retardants (FR) were studied. Asphalt binders were artificially aged in the rolling thin film oven (RTFOT) and Pressure Aging Vessel (PAV). The flame retardancy of modified asphalt binders were characterized using limited oxygen index (LOI), and the effects of aging on the properties of asphalt binders were studied using Brookfield viscometer test and dynamic shear rheometer test. Experimental results indicated that the flame retardancy of asphalt binder was increased after aging. But the increasing amount of LOI is low when the modified asphalt binder containing more flame retardants. The variation of the LOI, softening point, penetration, ductility and viscosity of asphalt binder decreased with flame retardant content increasing, meaning the flame retardants can improve the thermo-oxidative aging resistance of asphalt binder. Furthermore, the G*/sin δ, stiffness and m-value of flame retardant modified asphalt binders display smaller changes after two different aging.