Understanding Mechanisms of Raveling to Extend Open Graded Friction Course (OGFC) Service Life

To understand the mechanisms of raveling in open graded friction course (OGFC) mixtures, this project was divided into experimental measurements and finite element (FE) modeling. For the experimental part, mixtures with good and poor field performance with respect to raveling were selected and some variations were added. A field visit and forensic analysis of cores obtained from the corresponding field projects revealed poor drainability, lower binder content, and finer gradation than the mix design requirements. The aggregates and binders were characterized using standard and advanced techniques to determine their propensity to raveling. The six mixtures included in the study were also characterized in the laboratory using permeability, Cantabro loss, indirect tensile (IDT) strength, and Hamburg wheel tracking test. The Cantabro loss test was the best predictor of the durability of the mixtures when compared to observed field performance. American Association of State Highway and Transportation Officials (AASHTO) T 283 and the moisture induced stress tester (MIST) device were used to evaluate the effect of moisture on the mixtures' IDT strength and Cantabro loss. All mixtures showed minimal impact from the conditioning protocols, especially MIST conditioning. A finite element numerical model was also developed to better identify the mechanisms associated with the initiation and progression of raveling in OGFC. The two-dimensional model consisted of a moving wheel load passing over a typical OGFC layer on top of a regular pavement structure. The OGFC was modeled using microstructures obtained with X-ray computed tomography techniques. Various parameters related to the OGFC mixture (i.e., internal factors) and to climatic, traffic, and pavement conditions (i.e., external factors) were evaluated. The results were analyzed using probabilistic principles and suggested that the most relevant mixture-related factors increasing the chances of raveling are binder content and air void content. Extreme temperatures, high traffic loads, and slow speed vehicles were also identified as detrimental, while the structural capacity of the pavement located underneath the OGFC was identified as the least significant parameter in promoting raveling.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 272p

Subject/Index Terms

Filing Info

  • Accession Number: 01596683
  • Record Type: Publication
  • Contract Numbers: BDR74–977–04
  • Created Date: Apr 8 2016 10:10AM