Superpave In-Situ Stress/Strain Investigation, Phase II Volume III: Field Data Collection and Summary

Phase II of the PennDOT-sponsored project Superpave In-Situ Stress/Strain Investigation (SISSI) was initiated in June 2006 and completed in November 2008. This phase of the project was focused on extensive analysis of the collected data during Phase I and implementation of results from Phase I. Field-focused efforts during Phase II consisted of collection of pavement condition data, dynamic data, falling weight deflectometer data, traffic data, in-situ modulus data, and environmental data. All SISSI sites appeared to be in good shape except for the two overlaid pavement sections at the Warren and Delaware sites. At these two sites, a significant number of the longitudinal cracks at the lane-lane and lane-shoulder joints were probably due to poor construction. Transverse cracks on the pavement surface may be induced by underlying concrete slabs. Durability of Superpave mixes was of concern at two of these sites, Warren and Mercer. The project's last pavement condition survey at the Warren site indicated no cracking of the pavement mat at the site even though minor to moderate raveling and loss of fine was evident at the vicinity of the longitudinal joint. The minor to moderate raveling observed at the Mercer site is probably an indication of insufficient binder content for the mix used at this site. In general, some Superpave mixes have demonstrated that they are highly resistant to rutting, and this excellent rut resistance has come at the cost of lower durability in some cases. In general, the field-measured rutting, after 5 to 8 years of service, ranged from 2.5 to 8.5 millimeters, indicating excellent rut resistance of SISSI mixtures at all of the sites. Dynamic data collected during Phase II indicated significantly larger strain levels induced in the pavement during warmer times and lower speeds compared to colder seasons and higher speeds. Backcalculated moduli of asphalt concrete from FWD measurements were compared with the laboratory-obtained elastic moduli. The comparisons indicated that the backcalculated moduli were always higher than the laboratory determined values. The present report is one of four volumes, Volume I: Summary Report; Volume II: Materials Characterization; Volume III: Field Data Collection and Summary; Volume IV: Mechanistic Analysis and Implementation.


  • English

Media Info

  • Media Type: Web
  • Edition: Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 313p

Subject/Index Terms

Filing Info

  • Accession Number: 01146796
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-PA-2009-009-999012 HA 2006-02, PTI 2009-18
  • Contract Numbers: Contract No. 999012 Project HA2006-02
  • Created Date: Dec 7 2009 1:17PM