A comprehensive characterization of asphalt mixtures in compression.

Details

• Creators:
  Zhang, Yuqing ; Luo, Rong ; Lytton, Robert L.
• Corporate Creators:
  Texas A&M Transportation Institute
• Corporate Contributors:
  University Transportation Centers Program (U.S.)
• Subject/TRT Terms:
  Anisotropy (Physics) Asphalt Mixtures Asphalt Pavements Compression Laboratory Tests Mathematical Models Pavement Distress Rutting Viscoplasticity
• Publication/ Report Number:
  SWUTC/13/600451-00006-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  Southwest Region University Transportation Center (U.S.)
• Abstract:
  Permanent deformation (i.e., rutting) is one of the major distresses in asphalt pavements, and it consists of
  
  irrecoverable deformation due to viscoplastic flow and viscofracture fatigue damage. The mechanisms of rutting have not
  
  been well addressed due to the complexities of asphalt mixture including (a) distinctions between compression, extension,
  
  and tension; (b) rate and temperature dependence; (c) dilative volumetric change; (d) frictional material with cohesion;
  
  (e) inherent anisotropy due to preferential aggregates’ orientation; (f) crack-induced anisotropy due to crack growth;
  
  (g) strain hardening during viscoplastic accumulation; and (h) strain softening during viscofracture evolution.
  
  In this project, all of the aforementioned fundamentals of asphalt mixtures were simultaneously characterized by a
  
  comprehensive viscoplastic-fracture mechanistic model, which was incorporated with (a) a modified effective stress to
  
  consider the inherent anisotropy and the crack-induced anisotropy due to viscofracture cracking in compression; (b) a
  
  smooth and convex Generalized Drucker-Prager (GD-P) yield surface; (c) a non-associated viscoplastic flow rule; (d) a
  
  rate- and temperature-dependent strain hardening rule; and (e) a viscofracture evolution that was modeled by an
  
  anisotropic damage density-based pseudo J-integral Paris’ law. The model parameters were related to fundamental material
  
  properties that were measurable and understandable for civil engineers. A systemic testing protocol including five
  
  individual test methods were proposed to determine the model parameters and material properties. The test protocol was
  
  demonstrated to be efficient, as one asphalt mixture could be completely characterized within 1 day. The GD-P yield
  
  surface model was validated by octahedral shear strength tests at different normal and confining stresses. The GD-P model
  
  was able to characterize the full range of the internal friction angles from 0 to 90 degrees. In contrast, the widely used
  
  Extended Drucker-Prager (ED-P) model can only be used for a material that has an internal friction angle less than 22
  
  degrees due to the convexity criterion of the yield surface.
  
  
• Format:
  PDF
• Funding:
  DTRT12-G-UTC06
• Collection(s):
  University Transportation Centers US Transportation Collection
• Main Document Checksum:
  urn:sha256:dcffc61e49a5953a46010b5d6471cb438f9c24c1d6101d925d89d33d32730d8f
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/26647/dot_26647_DS1.pdf
• File Type:
  [PDF - 2.81 MB ]