Investigation of Asphalt Interlayers underneath Concrete Pavements

Logos of project participants

This research project aims on optimizing the construction method of the asphalt interlayer underneath a concrete pavement in terms of mechanical and hydraulic properties. For this purpose, investigations will be carried out on existing asphalt interlayers under concrete ceilings and possibly related layers. Usually nonwoven fabric is placed between the concrete pavement and the hydraulically bound base course. In an implementation with the variant investigated here, the nonwoven fabric is omitted, which is why this design has great potential, especially in terms of reusability and recyclability (Weingart & Wieland, 2009).

Chair and Institute of Highway Engineering of RWTH Aachen University carries out extensive investigations on cores from existing roadways that have been paved using this construction method. Among other things, this aims on gaining knowledge about the asphalt used and its condition. Based upon this information, materials to use for the installation of this construction method at the Institute’s test track are selected. Numerous drill cores will be taken from the test track to investigate the layer compound, asphalt deformation stability and bearing capacity.

In the context of this project not only mechanical properties are relevant. Hydraulics also plays an important role. Therefore, drainage and pumping effect in the joint area are also considered within the project.



Federal Highway Research Institute (BASt)



ISAC Forschung gGmbH


Milad Moharekpour, M. Sc.