Evaluation of empirical and fundamental test methods for permanent deformations of bituminous bound materials.

The new European Standards within the EN 13108 series specify several test methods for evaluating permanent deformation behavior of bituminous bound mixtures. In these standards two ways of addressing requirements for asphalt concrete are described: an empirical approach that specifies asphalt concrete in terms of compositional recipes and requirements for constituent materials with additional requirements based on performance related tests (also called empirical tests), such as wheel tracking tests (WTT). The other approach is the fundamental approach that specifies asphalt concrete in terms of performance-based requirements and test methods (also called fundamental tests), such as triaxial cyclic compression tests (TCCT) linked to limited prescription of composition and constituent materials. As part of an European research project, called SAMARIS, several laboratory tests (empirical wheel tracking tests WTT and fundamental cyclic compression tests CCT) and field experiments (full scale tests with alternate loading test devices ALT) on the same hot mix asphalt (HMA) materials have been performed in different laboratories. For the first time, tests results obtained from all these different test methods have been compared to achieve information about their comparability, in particular the comparability of the different wheel tracking test WTT procedures (specified in EN 12697-22) for possible future rationalization of the European Standards EN13108 series. In this paper some test results of these permanent deformation tests (WTT, ALT and CCT) are presented and compared according to their comparability (A). For the covering abstract of the conference see ITRD E212343.