Flame-retarding effects and combustion properties of asphalt binder blended with organo montmorillonite and alumina trihydrate

The flame-retarding effects, synergistic effect, and combustion properties of asphalt binder modified with organo montmorillonite (OMMT) and alumina trihydrate (ATH) were investigated on the basis of the limiting oxygen index (LOI) and a combination of thermogravimetry (TG) and Fourier transform infrared spectrometer (FTIR). The results indicated that there existed a synergist flame-retarding effect between OMMT and ATH. Moreover, the flammability of the OMMT/ATH compound was significantly improved as compared to individually adding either OMMT or ATH into base asphalt. Considering the flammability standard and synergy effect, the optimum content of OMMT and ATH was 1% and 3%, respectively. The amount of volatiles released from OMMT/ATH modified asphalt was much less than that from the base asphalt and the thermal stability of OMMT/ATH modified asphalt was superior to that of base asphalt. It is concluded that OMMT/ATH compound may be used as a new kind of environment-friendly flame retardant and smoke suppressant for asphalt binder.