Volume 37, Issue 5 (September 2009)
Investigation on the Bulk Performance and Microstructure of Emulsion-Based, Cold In-Place Recycling Mixtures
Cold in-place recycling (CIR) using asphalt emulsion is a cost-effective method for the preventive and corrective maintenance of existing pavements. The objectives of this study were to evaluate the recycling mixture’s macroscopic performance and to analyze the microstructure of the mastics using a scanning electron microscope (SEM). The overall performance of the recycling material was evaluated for retained stability, immersed freeze-thaw indirect tension tests, and rut testing. Additionally, the surface micro-profiles of three mastic classes were analyzed using SEM. The results of the bulk property analyses indicated that the addition of cement improved the performance of the recycling mixtures. The SEM analyses showed that cement has an effect similar to fiber-reinforcement in cement-treated asphalt emulsion CIR mixtures. Further, the results indicated that the mechanism of cement action is consistent with the results of the overall mixture performance properties.