Effect of deicing solutions on the tensile strength of micro- or nano-modified asphalt mixture

This paper reports on the potential benefits of micro-or nano-sized materials for asphalt mixtures used on pavements, specifically when they are exposed to water or deicing solutions. Asphalt mixtures were prepared with various amount of nanoclay and/or carbon microfiber, and compacted using the Superpave (TM) gyratory compactor. Moisture susceptibility and deicer impacts were assessed by exposing the samples to water or deicing chemicals (NaCl, MgCl2 and CaCl2), and seven freeze-thaw cycles, in a modified AASHTO T283 test. Comparisons of micro-or nano-modified asphalt mixtures exposed to deicers are made based on results of indirect tensile strength tests, which preliminarily demonstrate the great potential of using microfibers and nanoclays in asphalt mixture for improved performance. Based on the results, it was found that the addition of nanoclay and carbon microfiber would improve a mixture's moisture susceptibility performance or decrease the moisture damage potential in most cases. The detailed effects of deicing solutions on the tensile strength of micro-or nano-modified asphalt mixture are discussed in this paper. (C) 2010 Elsevier Ltd. All rights reserved.