Sustainability of cold recycled mixture with high reclaimed asphalt pavement percentages

The main goal of this study is to evaluate cold mixtures incorporating various percentages of reclaimed asphalt pavements (RAP) which is a typical sustainability technique to enhance the modern flexible pavement technology. The physical properties of RAP materials, new emulsion asphalt and new aggregate have been tested to evaluate the characteristics of these materials. Two mix design methods have been developed for control cold mix without RAP and recycled cold mixes containing 25 to 90 % of RAP by weight of total aggregate. First mix design depended indirect tensile strength as an indicative measure to determine optimum emulsion asphalt content while the second mix design method used Asphalt institute method (MS-14 and MS-21) . It found that Asphalt institute method required higher percent of optimum asphalt content than ITS method. The test results indicated that the recycled cold mixes containing high percent of RAP (75 to 90 %) are superior to control cold mix in traffic loading resistance and moisture susceptibility.