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Incremental Viscoelastic Damage Contact Models for Asphalt Mixture Fracture Assessment

Authors :
Gustavo Câmara
Rui Micaelo
Nuno Monteiro Azevedo
Hugo Silva
Source :
Infrastructures, Vol 9, Iss 7, p 118 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

Asphalt mixtures are widely used as a surfacing material for pavements due to their several advantages. For this reason, robust numerical models still need to be developed to improve the understanding of their fracture behaviour. Recently, an incremental generalised Kelvin (GK) contact model that relates increments in contact displacements with increments in contact forces was proposed to assess the viscoelastic behaviour of asphalt mixtures within a discrete element method (DEM) framework. In this work, the contact model is extended to allow its application to asphalt mixture fracture studies. Two damage models—a brittle and a bilinear softening—coupled with the GK contact model are proposed to consider damage initiation and propagation. A parametric study is presented that assesses the impact of the GK-Damage parameters, showing a sensitivity to the loading velocity and the Maxwell elements, particularly its viscosity element, on the stress–strain response of a single contact. A reduced-size numerical mastic is initially used to speed up the calibration process of the GK-Damage contact parameters, with subsequent validation on a specimen with real experimental dimensions. It is shown that the proposed calibrated damage models can successfully reproduce the time-dependent behaviour, peak stress, and crack path observed in experimental results, highlighting the benefits of the adopted methodology. For the GK-Bilinear model, the fracture energy and maximum contact tensile stress are shown to adjust both the peak stress and softening response. Uniaxial tensile tests on asphalt mixtures indicate that the GK-Bilinear model provides a more realistic characterisation of fracture development. A higher susceptibility to damage at aggregate-to-mastic contacts compared to contacts within the mastic phase is identified.

Details

Language :
English
ISSN :
24123811
Volume :
9
Issue :
7
Database :
Directory of Open Access Journals
Journal :
Infrastructures
Publication Type :
Academic Journal
Accession number :
edsdoj.371264d2644870b83436a5015048d9
Document Type :
article
Full Text :
https://doi.org/10.3390/infrastructures9070118