ABSTRACT
ABSTRACT: Permanent deformation in terms of rutting is a major deterioration mode of bituminous bound pavements. The Triaxial Cyclic Compression Test (TCCT) is a scientifically accepted and standardized test method to assess the resistance to permanent deformation. In most cases, TCCT is carried out with cyclic axial loading and constant confining pressure. In road pavements dynamic traffic loading due to passing tires leads to dynamic confining pressures. Thus, to bring the TCCT closer to reality, within the study presented in this paper, the radial response and its phase lag to axial loading in standard TCCTs is measured and an enhanced TCCT with cyclic confining pressure which takes into account the viscoelastic material response in terms of radial phase lag to axial loading is introduced. In a subsequent test program TCCTs with various confining pressure amplitudes are run on an AC 11 70/100 and results from standard and enhanced TCCTs are analyzed and compared in terms of resistance to permanent deformation. It is shown that the resistance to permanent deformation increases significantly when the viscoelastic material response is taken into account in the TCCTs with cyclic confining pressure.
