The falling weight deflectometer (FWD), a nondestructive testing device, is commonly used for the structural evaluation of pavements. The FWD equipment simulates the effect of a vehicle wheel load on the pavement and measures the response of the pavement at various locations in terms of deflections. Pavement layer parameters are then determined (commonly referred to as backcalculation) and incorporated into the pavement design. FWD testing was performed to evaluate the effectiveness of a resurfacing program designed by the New Jersey Department of Transportation (NJDOT) forces for a 12-mi (19.3-km) eastbound section of Interstate 78 in New Jersey. The resurfacing project was designed based on material parameters estimated from a visual distress survey and pavement coring. The FWD testing was performed both before and after milling and resurfacing of the hot mix asphalt pavement. The FWD test data were backcalculated using the PADAL program to determine the elastic modulus of asphalt concrete pavement, subgrade resilient modulus, and the effective structural number of the roadway. A follow-up design that was performed in accordance with the AASHTO Guide for Design of Pavement Structures indicated that the structural number of the pavement had increased an average of 1.6, with a service life of 15 to 19 years. FWD results also indicated that few sections of the roadway had higher deflections and needed more extensive rehabilitation. The service life of the overlay for these sections was estimated to be approximately 12 to 13 years. This paper intends to highlight the importance of FWD testing and the backcalculation procedure as a tool for optimizing project level design efforts. This project confirmed that FWD testing is instrumental in identifying deficient sections, optimizing pavement treatments, and therefore providing the most cost-effective solution for those charged with managing their project resources. Demonstrating the success of using FWD, NJDOT incorporated this approach for the 12-mi (19.3-km) segment of Route 78 in the westbound direction the following year.

  • Availability:
  • Supplemental Notes:
    • This entry in the TRIS database is made from the hardback copy of the conference proceedings, which are also available on CD-ROM.
  • Corporate Authors:

    Technomic Publishing Company, Incorporated

    851 New Holland Avenue, Box 3535
    Lancaster, PA  United States  17604
  • Authors:
    • Tabrizi, K
    • Ganji, V
    • Sauber, R
  • Conference:
  • Publication Date: 2000


  • English

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 145-150

Subject/Index Terms

Filing Info

  • Accession Number: 00793117
  • Record Type: Publication
  • ISBN: 1566769493
  • Files: TRIS
  • Created Date: May 3 2000 12:00AM