Effects of nanoclay on rutting and fatigue resistance of bitumen binder

Nanoclays are a new generation of processed clays of interest in a wide range of high performance composites. Nanoclay is defined as clay that can be modified to make the clay complexes compatible with organic monomers and polymers. Here, it can be said that polymeric nanocomposites are among the most exciting and promising classes of materials discovered recently. A number of physical properties are enhanced successfully when a polymer is modified with a small amount of nanoclay on condition that the clay is dispersed at the nanoscopic level. This research has accomplished a comparative rheological test on unmodified and nanoclay modified bitumen. For this, two types of nanoclay were used: Nanofill-15 and Cloisite-15A. X-ray diffraction has been used to study the nanostructure exfoliation of nanoclay platelets in bitumen. The results show that compared to unmodified bitumen, the nanoclay modification leads to changes in rheological parameters by increasing stiffness and decreasing the phase angle, hence it can also reduce aging effects in bitumen. Further, comparison of the rutting parameter (G*/sin delta) shows that the nanoclay modification could increase the rutting resistances of bitumen and the improvement is dependent upon the type and amount of nanoclay. The fatigue resistance parameter (G*/sin delta) at low to medium temperatures shows that the nanoclay modification reduces the fatigue life, however it exhibits the same fatigue life as that of the unmodified bitumen after a particular aging condition.