Three-Dimensional Micromechanical Pavement Model Development for the Study of Block Cracking

Block cracking in asphalt pavements is a major form of surface cracking but has been the subject of very few scientific investigations. The use of recycled materials and additives that potentially increase material embrittlement continues to be on the rise, and thus, understanding the mechanisms behind block cracking and tailoring preventive solutions merits rigorous investigation. In this paper, a 3D viscoelastic and inhomogeneous microstructure-based pavement model subjected to thermal straining is introduced. A typical PG 64-22, dense-graded Illinois asphalt surface mixture was adopted as the baseline material, which typically experiences block cracking later in its service life. Effects of aging and cooling rate on block cracking extent and depth were studied, along with the mechanisms behind the development of hexagonal-shaped crack patterns. Discrete element simulations showed that initial block cracking mostly occurs in the upper one-to-two centimeters of the surface, which agrees with field observations. In addition, it was found that block cracks form at a warmer temperature than that associated with thermal cracking. This implies that current test criteria for thermal cracking mitigation may need to be updated or supplemented in order to control block cracking. In addition, the techniques presented herein can be extended to identify candidates for preventive maintenance, and in developing tailored maintenance techniques. For the latter, it may be helpful to employ surface health monitoring tools such as recently developed non-destructive testing methods to characterize pavement surface condition.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AFK50 Standing Committee on Structural Requirements of Asphalt Mixtures.
  • Corporate Authors:

    Transportation Research Board

  • Authors:
    • Wang, He
    • Buttlar, William G
  • Conference:
  • Date: 2019


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References;
  • Pagination: 4p

Subject/Index Terms

Filing Info

  • Accession Number: 01698402
  • Record Type: Publication
  • Report/Paper Numbers: 19-03028
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 7 2018 9:25AM