Sustainable asphalt concrete containing high reclaimed asphalt pavements and recycling agents: Performance assessment, cost analysis, and environmental impact

In this study, mechanical performance, environmental impacts, and economic benefit criteria are considered so as to introduce sustainable asphalt mixtures containing a high content of reclaimed asphalt pavements. The low-temperature cracking, moisture susceptibility, fatigue cracking, and rutting resistance of asphalt concrete are the most common deficiencies of rejuvenated reclaimed asphalt mixtures. Therefore, to analyze the mechanical characteristics, different experimental tests including Marshall Stability, indirect tensile strength, tensile strength ratio, semi-circular bending (at low and intermediate temperatures) are applied, and their results are taken into consideration as determinate mechanical performances in optimizing the mixture. The percentage of landfill embedment, saving in energy consumption, and the amounts of harmful emissions are utilized to compare the environmental influences of eco-friendly and the virgin mixtures. Drawing the results of experimental tests and statistical analysis (i.e., ANOVA, and Tukey pairwise comparison), the mechanical characteristics of mixtures containing various content of reclaimed asphalt pavements (i.e., 30%, 60%, and 100%), waste engine oil, and supplementary binder modified with crumb-rubber simultaneously are better than or equal to that of the conventional mixture. The environmental analysis reveals that the refined mixture is by far valuable than the virgin mixture. The proposed asphalt concrete incorporating the 100% of reclaimed asphalt pavements significantly reduces the pollution generated by the production and preparation of materials to manufacture asphalt mixture. Moreover, the energy consumed to manufacture, the percentage of landfill embedment, and the rate of economic conservation considerably decrease in suggested asphalt concretes containing different content of reclaimed asphalt pavements in comparison with the virgin mixture. This environmental Protection of the examined asphalt concretes enhances as the content of reclaimed asphalt pavements increases. (C) 2019 Elsevier Ltd. All rights reserved.