Field Evaluation of Alternative Isolation Joints at O'Hare International Airport

Airfield isolation joints are specified to separate horizontal movement between two adjacent concrete pavements. Typically, these are a thickened edge joint without any man-made connection, which requires a 25% thicker slab to compensate for the higher free edge stresses. Thickened edge joints are more difficult to construct and thus require more time and resources to complete. Recently, the Federal Aviation Administration (FAA) introduced an alternative design for isolation joint with embedded steel reinforcement near the slab bottom allowing the normal slab thickness to be maintained. In this study, two isolation joint types were constructed at Chicago O’Hare International Airport. One section followed the recently recommended FAA steel reinforcement design and the other section was constructed with macro-fiber reinforced concrete. Embedment gages were placed in the freshly cast concrete as well as gages on the steel reinforcing bars to monitor the strains under aircraft loading. Dynamic strain data was collected during a night of aircraft taxiing over the joint. In addition, heavy weight deflectometer (HWD) testing was conducted at a separate time to measure the isolation joint effectiveness. The alternate joint designs were modeled using 2D finite element analysis for comparison to the experimental results and to determine the critical tensile stresses. The field analysis indicates that the steel or macro-fiber reinforced joint design with a stabilized base should prevent the tensile stresses in the pavement from causing premature failure of the concrete isolation joint.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; References; Tables;
  • Pagination: 14p
  • Monograph Title: 2014 FAA Worldwide Airport Technology Transfer Conference Proceedings: Innovations in Airport Safety and Pavement Technology

Subject/Index Terms

Filing Info

  • Accession Number: 01538252
  • Record Type: Publication
  • Report/Paper Numbers: P10075
  • Files: TRIS, ATRI, USDOT
  • Created Date: Sep 9 2014 6:58AM