Effect of Organoclay Modified Binders on Fatigue Performance

摘要

Organoclay modification is receiving attention as a nano-modifier for asphalt binders. Nanoparticles are able to effectively mend the damaged sites of the nanocomposite without external intervention. Particle-polymer interaction results in packing particles into developed cracks, thereby mending the cracks during patch formation. This study investigates the rheological properties of organoclay modified binders with a focus on their fatigue properties. To this end, the dissipated energy concept, the ratio of dissipated energy change and plateau value (PV) energy were examined during fatigue tests using a dynamic shear rheometer. The effects of strain level, frequency and temperature on unaged and aged neat PG64-22 asphalt binder modified with organoclay were evaluated in strain-controlled time sweep fatigue tests. Also evaluated was the effect of rest periods introduced at cycles corresponding to different damage levels over the course of the time sweep tests on the fatigue life of neat and modified binders. It was found that increased amounts of organoclay and decreased levels of strain led to lower PV values and higher fatigue resistance. It was also found that organoclay modified binders heal more effectively during the rest periods, which results in higher fatigue life.