Fatigue investigation of mastics and bitumens using Annular Shear Rheometer prototype equipped with wave propagation system

Abstract

A research project on fatigue behavior of bitumens and mastics is developed at University of Lyon, ENTPE/DGCB in collaboration with TOTAL Company. An innovative device, the Annular Shear Rheometer (ASR), is used to perform advanced experimental investigation. It allows practicing fatigue tests, which could be considered as homogenous, on larger scale specimen than traditional other devices. This apparatus allows measuring the linear viscoelastic (LVE) shear complex modulus (G*) of bituminous materials for small strain amplitudes, and the non linear modulus Ge* for higher strain levels applied during fatigue tests. Different types of materials, including pure bitumens and mastics (phase composed of bitumen and filler) are tested. A new measurement dynamic system consisting of wave propagation, equips the ASR. This system allows sending ultrasound at high frequencies (between 100 and 600 kHz). In this paper, the ASR and the wave propagation system, as well as the fatigue testing procedure and the tested materials are presented. During fatigue tests, the evolution of complex modulus from cyclic and dynamic and non linear modulus is observed. © RILEM 2012.