Early-Life Performance of Cold-in-Place Pavement Recycling with Foamed Asphalt Technique

The cold-in-place recycling technique with foamed asphalt stabilization was used to rehabilitate a severely damaged, heavily trafficked highway, part of the Trans European Network. Lack of experience, at least as far as the performance of the aforementioned technique for heavy-duty pavements was concerned, was the main reason for the Greek Ministry of Public Works to undertake a field experiment incorporating semirigid and flexible pavements. To achieve this goal, a comprehensive monitoring and data analysis research study was performed; it concentrated on the falling weight deflectometer as a major tool for the in situ evaluation of early-life performance of the recycled pavement. In addition, as-built roughness and ground-penetrating radar measurements, accomplished with in situ material coring and related laboratory tests, were performed. The roughness data analysis raised several issues concerning the construction of the recycled layer. According to the deflection analysis, an improvement in the recycled pavement structural condition was observed during the early life. The foamed asphalt material of the semirigid pavement proved to be stiffer than that of the flexible pavement. Furthermore, significant differences between pavement design parameters and related in situ characteristics were obtained through the strain response analysis.