Analysis of the strength of hot in-place recycled asphalt, its affecting factors and its comparison with conventional methods

In recent decades, economic development and population growth in the world has led to the expansion of road networks. Therefore the use of optimum methods for repairing and maintenance of these roads is considered as an important value. Today one of the options in this regard, is the use of asphalt recycling technology. The present study which took place in the summer of 2015 in Iran, Lorestan province, is in line with this target with the goal to compare the recycling of asphalt with the common methods as well as the qualitative assessment of each method. In this study which was based on the analysis of asphalt samples from the Khorramabad-boroujerd route and samples from Arak-Qoms hot in-place recycling project, 9 laboratory samples were made using recycled asphalt pavements in accordance with the regulations of hot asphalt recycling of Iran. These samples were made using 80% recycled asphalt pavements which were collected from 3 different locations from lorestan province, as well as 20% raw and new materials. After conducting the quality control tests for asphalt on the 9 samples, one of the 9 samples that had higher technical specifications and was more in accordance with the Arak-Qoms recycling project mix design, was chosen as the optimal sample. The optimum samples test results were analyzed, compared and evaluated with the two projects mentioned above. The results showed that although both methods were in range with the minimum and maximum technical quality specifications, the recycling method had higher quality and technical specifications.