Organic Montmorillonite Modified Asphalt Materials: Preparation and Characterization

Organic montmorillonite (OMMT) modified asphalt was prepared with the melting intercalation technology. The distribution of OMMT layers in matrix asphalt was characterized through x-ray diffraction (XRD) and transmission electron microscope (TEM), and the effect of OMMT on physical properties and dynamic rheology of matrix asphalt were studied as well. It was found that OMMT homogeneously dispersed in the modified asphalt and intercalated OMMT/asphalt nanocomposites were prepared by means of melt extrusion. Additionally, from the penetration, softening point, and dynamic shear rheometer (DSR) testing result, it was observed that the OMMT obviously improved the high-temperature stability, temperature serviceability, and rut resistance of the matrix asphalt. The bending beam rheometer (BBR) results indicated that the OMMT modified asphalt with OMMT dosage of 3 % exhibited the lowest stiffness and highest resistance to low temperature cracking, and had less effect on the relaxation of stress in low temperature in comparison with OMMT modified asphalt with OMMT dosage of 1 % and 5 %. Furthermore, it was found that the optimal dosage of OMMT was 3 %.