Strategy for improving the effect of hot in-place recycling of asphalt pavement

Abstract

The material composition of hot in-place recycling asphalt mixture (HIRAM) fluctuates violently during construction in the field, effecting the hot in-place recycling (HIR) construction quality. In addition, construction cost optimization and carbon emission control are also crucial factors to consider in today's pavement projects. To maximize the benefits of HIR maintenance technology, a systematic procedure for designing the HIRAM material composition and a strategy for optimizing the construction parameters are proposed by considering the RAP variability, construction costs, and carbon emissions. The management strategy for controlling the construction quality of HIR in the field is also proposed, and the feasibility of the strategy for designing HIRAM material composition and optimizing the construction parameters is verified in engineering practice. The results show that there is a significant difference in RAP material composition at different road sections, and the procedure developed in this study can precisely design the HIRAM material composition based on the principle of similarity of RAP aggregate gradation via Fréchet similarity and K-means cluster analysis, and the accuracy of HIRAM gradation design can be improved to 26.5 %. The HIR construction parameters can be optimized by applying the warm mix asphalt technology based on the multi-objective optimization model. At the same time, the benefits are evaluated, showing that the total construction cost and CO2 emissions of the project can be reduced by 6.67 % and 16.81 %, respectively. Those working in the field of asphalt pavement maintenance may be interested in this strategy, as this study was done intentionally for practical applications.