عنوان مقاله [English]
Because microsurfacing is one of the most important methods in preventative maintenance of pavements, it is important for road and urban development departments that this type of surface treatment is designed and optimized to have the best performance and maximum service life. In this study, a special type of this cold asphalt mixture, which is made using mineral colored materials, was examined. In general, the aim of this study is to evaluate the applicability of using iron oxide red pigment in the microsurfacing mix design to change the color of this type of asphalt and evaluate its performance. In this regard, first, the physical and chemical specifications of aggregate and pigment materials were evaluated. Then to evaluate the performance of the microsurfacing mixtures containing pigments, 4 different compounds containing 0, 3, 6 and 9% of pigments were used in three different levels of bitumen emulsion. The results have been shown that mixtures containing red iron oxide pigments have passed the limitation of the International Slurry Surfacing Association (ISSA). The design results indicated that the mixtures containing red iron oxide pigment fulfilled the requirements of the regulations, and the mixture containing 9% of the iron oxide pigment had the best function among the mixtures. Also, this mixture had 1.1% more emulsion bitumen than the control sample in order to achieve the proper adhesion at the specified time. The results of the experiments on the other samples showed clearly that the mixtures containing red iron oxide pigment had a very good adaptation to the bitumen emulsion due to their favorable mechanical, chemical and physical properties. These features also led to the improvement of microsurfacing functions including the increased adhesion in 30 and 60 minutes by 41.6% and 21.7%, respectively, increase abrasion resistance by 27.92% and reduce vertical displacement by 52.5%.