Mechanistic-empirical asphalt overlay thickness design and analysis system.

Details

• Alternative Title:
  Project title: Development of an advanced overlay design system incorporating both rutting and reflection cracking requirements
• Creators:
  Zhou, Fujie ; Hu, Sheng ; Hu, Xiaodi ; Scullion, Tom
• Corporate Creators:
  Texas Transportation Institute
• Corporate Contributors:
  Texas. Dept. of Transportation. Research and Technology Implementation Office ; United States. Federal Highway Administration
• Subject/TRT Terms:
  Bituminous Overlays Mathematical Models Pavements--Texas--Overlays Overlays (Pavements) Pavements, Asphalt--Texas--Design And Construction
• Publication/ Report Number:
  FHWA/TX-09/0-5123-3
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas
• Edition:
  Technical report; Sept. 2007-Aug. 2008.
• Corporate Publisher:
  Texas Transportation Institute
• Abstract:
  The placement of an asphalt overlay is the most common method used by the Texas Department of Transportation (TxDOT) to rehabilitate
  
  existing asphalt and concrete pavements. The type of overlay and its required thickness are important decisions that TxDOT engineers make on a
  
  daily basis. To perform well, an asphalt overlay must have a balance of both good rut and crack resistance. Furthermore, overlay performance is
  
  highly influenced by many factors, such as existing pavement conditions, traffic loading, and environmental conditions. It has also recently
  
  become common practice to use two different materials in an overlay, the first being a crack resistant level up course and the second being a
  
  wearing surface. The properties of both overlay types have a big impact on performance. The main objective of the Research Project 0-5123 was
  
  to develop a comprehensive mechanistic-empirical (M-E) asphalt overlay design system to assist TxDOT engineers to make these design
  
  decisions.
  
  The design system developed incorporates models for both rutting and reflection cracking of the proposed overlay. The Paris’ law-based
  
  reflection cracking model was evaluated and recommended for use in this study. This model requires the use of both stress intensity factors (SIF)
  
  and fracture properties (A and n) for predicting crack propagation caused by both traffic loading and thermal effects. For practical implementation
  
  of the SIF concept, a total of 34 SIF regression equations were developed based on more than 1.6 million finite element computations. The
  
  required fracture properties can be easily determined using the Overlay Tester. The proposed reflective cracking model was calibrated using
  
  performance data from three HMA overlay field case studies and then verified using the California’s Heavy Vehicle Simulator test results. To
  
  predict asphalt overlay rutting, the well-known VESYS layer rutting model was used and later calibrated using the field rutting data from the
  
  National Center for Asphalt Technology (NCAT) test track 2006. The material properties required for this model are obtained from repeated load
  
  tests. The reasonableness and accuracy of the calibrated rutting was further verified by the field rutting data from NCAT test track 2000. Finally,
  
  the calibrated reflective cracking and rutting models were integrated into an asphalt overlay thickness design and analysis program. To assist in
  
  implementation, default values of material properties have been provided for all the overlay types currently used in Texas. The program provides
  
  the designer with a tool to evaluate on a project-level basis the impact of load transfer efficiency (LTE) on predicted life and to determine what
  
  level of LTE must be repaired in order to achieve adequate performance.
  
  In summary this study has developed a comprehensive overlay thickness design and analysis system based on solid engineering principles.
  
  The software package developed in this study has been provided to TxDOT. Based on the evaluations made in this study its predictions appear
  
  r ational and reasonable. This system is ready for state-wide pilot implementation.
  
  
• Format:
  PDF
• Funding:
  Project 0-5123
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:aa3ef4f2398ef1c9e2b8e00b289567096eaf665669d85cb1a3fe42e6c768b6fc3306cb6ab7ea96adb20f7a2c9f2ce656393353b0ee88b236c9db0a2f404e5d8f
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/16982/dot_16982_DS1.pdf
• File Type:
  [PDF - 8.57 MB ]