Effect of organic layered silicates on flame retardancy and aging properties of bitumen

The effect of organic layered silicates (OLSs) on the flame retardancy and aging properties of the bitumen was investigated as well as the microstructures of the binders. X-ray diffraction shows that organic rectorite (OREC) and organic montmorillonite (OMMT) modified bitumens form the intercalated nanostructures, while the organic expanded vermiculite (OEVMT) modified bitumen forms the exfoliated nanostructure. The mass change rate and viscosity aging index of the bitumen are decreased by OLSs after thin film oven test and pressure aging vessel aging. Compared with OREC and OMMT, OEVMT has more pronounced improvements in flame retardancy and aging resistance of bitumen.