Comportement du sable dans le domaine des petites et moyennes déformations : rotations "d\u27axes" et effets visqueux

L\u27étude du comportement du sable d\u27Hostun dans le domaine des petites et moyennes déformations est réalisée à l\u27aide du prototype, " T4CStaDy ", qui permet d\u27appliquer indépendamment Torsion, Compression et Confinement sur un Cylindre Creux. Des sollicitations cycliques de faibles amplitudes permettent de déterminer huit termes du tenseur rhéologique équivalent. Les modules d\u27Young et de cisaillement sont aussi déterminés par propagation d\u27ondes, à l\u27aide de capteurs piézoélectriques. Afin de modéliser le comportement du sable dans le domaine des petites déformations, une nouvelle loi hypo-élastique prenant en compte l\u27anisotropie induite et les rotations d\u27axes est développée. Les essais mettent en évidence le comportement visqueux du sable sec, par des périodes de fluage. Une modélisation basée sur un modèle rhéologique à trois éléments est proposée pour prendre en compte ces phénomènes visqueux

Stiffness of bituminous mixtures using ultrasonic wave propagation

Wave propagation tests were performed on several specimens of bituminous mixes. Back analysis is made within the framework of linear viscoelastic materials to obtain dynamic moduli. Comparison with moduli obtained from traditional cyclic tension-compression complex modulus test, shows that dynamic tests and cyclic tests results fit very well. A unique master curve is obtained and the time-temperature superposition is validated for very high frequencies (several 10 kHz). Simulation with the model developed at University of Lyon, ENTPE laboratory (2S2P1D) confirms the ability of this model to cover the wide frequency and temperature range. Furthermore, moduli obtained in different directions from dynamic (wave propagation) tests, reveal that different compaction techniques create different types of anisotropy

Softening and local self-heating of bituminous mixtures during cyclic loading

International audienc

Effect of Fatigue Cyclic Loading on the Linear Viscoelastic Properties of Bituminous Mixtures

International audienc

Anisotropy of bituminous mixture in the linear viscoelastic domain

International audienc

Seven-Parameter Linear Viscoelastic Model Applied to Acoustical Damping Materials

International audienc

Crack propagation characterisation of bituminous mixtures using a four-point bending notched specimen test

Fracture behaviour of bituminous mixture has been increasingly studied in the last decade for a more comprehensive and detailed approach which could be taken into account in the pavement design process. This study presents an investigation at the Université of Lyon/Ecole Nationale des Travaux Publics de l'Etat (ENTPE) on fracture behaviour of bituminous mixtures during crack propagation. The four-point bending notched fracture test which has been designed at ENTPE was used. A quite new methodology, which makes it possible to characterise fracture behaviour of tested mixtures during crack propagation tests, has been proposed and applied for these tests thanks to an improved crack length determination approach based on inverse analysis. According to this methodology, different fracture parameters such as fracture toughness and fracture energy can be evaluated at different moments during the crack propagation test for a given advancement of the crack tip

Nonlinearity of bituminous mixtures

International audienc

Reversible phenomena and fatigue damage during cyclic loading and rest periods on bitumen

International audienc

Influence of transient effects for analysis of complex modulus tests on bituminous mixtures

International audienc