Investigating Fatigue Behavior of Nanoclay and Nano Hydrated Lime Modified Bitumen Using LAS Test

Abstract

In this study, the effects of two nanomaterials—nanoclay and nano hydrated lime—on the fatigue properties of bitumen were investigated. Nano hydrated lime was produced in a laboratory using a planetary ball mill. The milling process was conducted in the specified conditions of speed, time of rotation, and ball to powder ratio (BPR). The processing conditions were determined by a trial and error procedure. With the aim of evaluating the fatigue life of modified mixes, various filler-bitumen combinations were tested under linear amplitude sweep (LAS) testing, which was performed using a dynamic shear rheometer (DSR) instrument. The results indicated that nanoclay at 6% level (by weight of bitumen) increased fatigue life of the binder by approximately 40%. The specimen that contained 10% nano hydrated lime showed the fatigue life that was 49% greater than that containing 10% hydrated lime. Based on the results of this research, 6% nanoclay and 5% nano hydrated lime were the optimum amounts of these materials to be added to bitumen for nanomodification purposes.