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Development of a stress-mode sensitive viscoelastic constitutive relationship for asphalt concrete: experimental and numerical modeling

Karimi, M. M ; Sharif University of Technology | 2017

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  1. Type of Document: Article
  2. DOI: 10.1007/s11043-016-9335-7
  3. Publisher: Springer Netherlands , 2017
  4. Abstract:
  5. Asphalt binder is responsible for the thermo-viscoelastic mechanical behavior of asphalt concrete. Upon application of pure compressive stress to an asphalt concrete specimen, the stress is transferred by mechanisms such as aggregate interlock and the adhesion/cohesion properties of asphalt mastic. In the pure tensile stress mode, aggregate interlock plays a limited role in stress transfer, and the mastic phase plays the dominant role through its adhesive/cohesive and viscoelastic properties. Under actual combined loading patterns, any coordinate direction may experience different stress modes; therefore, the mechanical behavior is not the same in the different directions and the asphalt specimen behaves as an anisotropic material. The present study developed an anisotropic nonlinear viscoelastic constitutive relationship that is sensitive to the tension/compression stress mode by extending Schapery’s nonlinear viscoelastic model. The proposed constitutive relationship was implemented in Abaqus using a user material (UMAT) subroutine in an implicit scheme. Uniaxial compression and indirect tension (IDT) testing were used to characterize the viscoelastic properties of the bituminous materials and to calibrate and validate the proposed constitutive relationship. Compressive and tensile creep compliances were calculated using uniaxial compression, as well as IDT test results, for different creep-recovery loading patterns at intermediate temperature. The results showed that both tensile creep compliance and its rate were greater than those of compression. The calculated deflections based on these IDT test simulations were compared with experimental measurements and were deemed acceptable. This suggests that the proposed viscoelastic constitutive relationship correctly demonstrates the viscoelastic response and is more accurate for analysis of asphalt concrete in the laboratory or in situ. © 2016, Springer Science+Business Media Dordrecht
  6. Keywords:
  7. Asphalt concrete ; Finite element modeling ; Indirect tension test ; Sensitivity to tension/compression stress mode ; User material (UMAT) subroutine ; Aggregates ; Anisotropy ; Asphalt ; Compressive stress ; Concretes ; Creep ; Finite element method ; Materials testing ; Stress analysis ; Stresses ; Tensile testing ; Viscoelasticity ; Anisotropic viscoelastic relationship ; Constitutive relationships ; Indirect tension tests ; Intermediate temperatures ; Non-linear viscoelastic modeling ; Stress modes ; User material ; Viscoelastic properties ; Mastic asphalt
  8. Source: Mechanics of Time-Dependent Materials ; Volume 21, Issue 3 , 2017 , Pages 383-417 ; 13852000 (ISSN)
  9. URL: https://link.springer.com/article/10.1007%2Fs11043-016-9335-7