In-situ characterization of foamed bitumen treated layer mixes for heavy-duty pavements

Abstract

As the cost of the hot mixed asphalt mixtures (HMA) continuously increases and the availability of good materials is limited, cold in-place recycling (CIPR) using foamed bitumen treatment offers an attractive alternative to other pavement rehabilitation options. Since there is a lack of sufficient experience concerning the early life pavement performance using the aforementioned technique for heavy duty pavements, the Greek Ministry of Public Works undertook a field experiment for the purpose of rehabilitating a severely damaged heavily trafficked highway, part of the trans European network (TEN). In order to achieve this goal, a two-year comprehensive monitoring of pavement performance and data analysis research study was performed by the Laboratory of Highway Engineering of the National Technical University of Athens (NTUA). This study focuses on the in situ characterization of foamed bitumen treated recycled pavement layer mixes using both in situ non destructive tests (NDTs) as well as laboratory tests on extracted cores accomplished with advanced analysis tools. The major findings of the research study are presented and discussed in the present work.

Keywords:

• Stiffness moduli
• FWD
• Back analysis
• GPR
• Foamix
• Recycling

Acknowledgements

This study was supported by the Greek Ministry of Public Works (EYDE/PATHE) in the framework of the second cohesion fund of the European Union (EU). The authors would like to express thanks to Wirtgen GmbH/HELMA, AKTOR SA and Loudon International that were involved in the design and construction process and to Professor Kim Jenkins (University of Stelenbosh) for offering valuable information.