Prediction of Creep Stiffness of Asphalt Mixture with Micromechanical Finite-Element and Discrete-Element Models

This study presents micromechanical finite-element (FE) and discrete-element (DE) models for the prediction of viscoelastic creep stiffness of asphalt mixture. Asphalt mixture is composed of graded aggregates bound with mastic (asphalt mixed with fines and fine aggregates) and air voids. The two-dimensional (2-D) microstructure of asphalt mixture was obtained by optically scanning the smooth surface of superpave gyratory compacted asphalt mixture specimens. For the FE method, the micromechanical model of asphalt mixture uses an equivalent lattice network structure whereby interparticle load transfer is simulated through an effective asphalt mastic zone. The ABAQUS FE model integrates a user material subroutine that combines continuum elements with viscoelastic properties for the effective asphalt mastic and rigid body elements for each aggregate. An incremental FE algorithm was employed in an ABAQUS user material model for the asphalt mastic to predict global viscoelastic behavior of asphalt mixture. In regard to the DE model, the outlines of aggregates were converted into polygons based on a 2-D scanned mixture microstructure. The polygons were then mapped onto a sheet of uniformly sized disks, and the intrinsic and interface properties of the aggregates and mastic were assigned for the simulation. An experimental program was developed to measure the properties of sand mastic for simulation inputs. The lab measurements of the mixture creep stiffness were compared with FE and DE model predictions over a reduced time. Results indicate both methods are applicable for mixture creep stiffness prediction.

  • Availability:
  • Supplemental Notes:
    • Abstract reprinted with permission from ASCE
  • Authors:
    • Dai, Qingli
    • You, Zhanping
  • Publication Date: 2007-2

Language

  • English

Media Info

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Filing Info

  • Accession Number: 01045097
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 21 2007 12:47PM