Volume 38, Issue 5 (September 2010)
Mechanical Behavior of Nanoclay Modified Asphalt Mixtures
Polymeric nanocomposites are among the most exciting and promising classes of materials discovered recently. A number of physical properties are successfully enhanced when a polymer is modified with small amount of nanoclay on condition that the clay is dispersed at nanoscopic level. In this research, comparative rheological tests on binders and mechanical tests on asphalt mixtures containing unmodified and nanoclay modified bitumen, were carried out. Two types of nanoclay were used: Nanofill-15 and Cloisite-15A. Rheological tests on binder were penetration, softening point, ductility, and aging effect. Mechanical tests on asphalt mixture were Marshall stability, indirect tensile strength, resilient modulus, diametric fatigue, and dynamic creep tests. Test results show that nanoclay can improve properties such as stability, resilient modulus, and indirect tensile strength and result in superior performance compared to that of unmodified bitumen under dynamic creep. Nanoclays do not seem to have beneficial effect on fatigue behavior in low temperature. Optimum binder content and void in total mixture increase by adding nanoclay to bitumen.