Complex reinforcement potential of inorganic nanoparticles in bitumen

Although the modification of bitumen using nanoparticles has become popular in research studies recently, the degree of modification they provide is still debatable. This paper discusses the effects of three nanoparticles (silicon dioxide, titanium dioxide and calcium carbonate) on the physical properties and rheological behaviour of bitumen. The microstructural properties were evaluated using X-ray diffraction (XRD) and the physical properties were assessed through penetration, softening point and ductility tests. A dynamic shear rheometer was used to investigate the rheological properties of the bitumen, and the results were analysed through the 2S2P1D master curve model and complex reinforcement coefficient R^*_M. The results of XRD indicated substantial changes in the bitumen structure after adding the nanoparticles. The results showed that the physical properties and rheological behaviour of bitumen were significantly altered by adding the nanosilica to bitumen. However, using the same amount of titanium dioxide and calcium carbonate as additives was less effective than the use of nanosilica. It was also found that the 2S2P1D model and complex reinforcement coefficient R^*_M were very practical for satisfactory modelling and comparing the rheological properties of nanoparticle-modified binders.