Modelling of low-temperature behaviour of cracks in asphalt pavement structures

Abstract

This paper examines the transient stress analysis of a multilayer pavement stmcture subjected to heat conduction and asssciated thefanoelastic effects by the cooling of its surface. In particular, the layered structure contains a transverse crack which can be created either during the construction of the pavement or during its service life-The numerical treatment of the transient stress analysis is achieved using a finite element scheme, which models the heat conduction and thermoelasticity of each component in the layered system and the singular stress field at the extremities of a crack. The numerical scheme is applied to examine the manner in which the propagation of ar m existing crack is influenced by the thermoelastic mismatch between the layers adjacent to the crack location. The analysis also illustrates the influence of the thermselastic mismatch between a cracked pavement and an overlay, in the suppression of crack propagation.Key words: fracture mechanics, pavement structures, low-temperature fracture, transient thermal effects, finite element modelling, stress intensity factors.Le grdsent article traite d'une amlyse des contraintes transitoires d'une chaussCe multicsuche qui a Ct C soumise h la conductisn de chaleur et a subi les effets thermoCiastiques associh au refrsidissement de sa surface. De f a~o n plus prCcise, B e systkme en couches comporte une fissure transversale crCCe soit durant la constmctisn de la chaussCe, soit durant sa durCe de vie utile. Le traiternent numCrique de I'analyse des contraintes transitoires est rCalisC par la rnCthode des 61Cments finis qui pemet de modCliser la conduction de chaleur et la thermoClasticitC de chaque composante d'une systkme en couches, ainsi que le champ des contraintes aux extrCmitCs d'une fissure. Le processus numCrique est utilisC pour examiner comment les conditions de propagation d'une fissure existante ssnt influenckes par le d6sCquilibre thermoklastique entre Bes couches adjacentes h la fissure. L9analyse dCmontae Cgalement l'effet du dCsCquilibre thermoClastique entre une chausske fissurCe et un aecouvrement, dans B'Climination de la propagation des fissures.

Effects of loading, geometry and material properties on fracture parameters of a pavement containing top-down and bottom-up cracks

“…Positive and negative T-stress values can result in reduction or enhancement of the fracture resistance in cracked pavements. However in most of previous research studies [4][5][6][7][8][9][10][11][12][13][14][15][16][17], the influence of such parameter has not been investigated for pavements with different geometrical and material characteristics subjected to traffic loading. Fig.…”

“…Shalaby et al [12] also investigated the influence of thermal stresses on mode I crack growth behavior of cracked asphalt overlays using two and three-dimensional finite element models in ANSYS software. In another research work, Selvadurai et al [13] modeled low temperature cracking behavior of a multi-layer pavement structure subjected to thermal loads using the framework of fracture mechanics. Karadelis and Lin [14] computed the value of energy release rate at the interface of concrete/overlay pavement using crack closure method.…”

Transient Thermo-Viscoelastic Response of a Crack in a Layered Structure

“…The attention is restricted to the examination of two-dimensional plane-strain problem in which the surface of the viscoelastic layer is subjected to a sudden decrease in the temperature, in the form of a step function of time. The results of a previous investigation [5] have shown that the rapid reduction in the surface temperature of an elastic asphalt layer results in the development of the maximum stress intensity factor at the crack tip. The geometry of the region in relation to the surface crack is shown in Fig.…”

“…In particular, the study of the mechanical behavior of pavement structures that are subjected to low-temperature effects is regarded as an important aspect of improving pavement performance and design. These studies become more important in situations where defects such as cracks, delaminations, voids, etc., are induced in the asphalt pavements and overlays either during its construction or during its service life 11-31, Recent studies [4,5] have examined the behavior of a pavement structure with a surface crack that is subjected to the combined effects of heat conduction and associated thermoelastic effects. Such surface cracks could be created either during construction of the asphalt layer or during its service life.…”

Digital image processing for aggregate orientation in asphalt concrete mixtures

“…The composite materials are always assumed to be homogeneous and isotropic and their heterogeneous and anisotropic properties are largely ignored (Selvadurai et al 1990). …”