Structural Factors of Jointed Plain Concrete Pavements: SPS-2--Initial Evaluation and Analysis

The SPS-2 experiment, "Strategic Study of Structural Factors for Jointed Plain Concrete Pavements (JPCP)," is one of the key components of the Long Term Pavement Performance (LTPP) program. The main objective of this experiment is to determine the relative influence and long-term effectiveness of JPCP design features (including slab thickness, portland cement concrete flexural strength, base type and drainage, and slab width) and site conditions (traffic, subgrade type, climate) on performance. This report documents the first comprehensive review and evaluation of the SPS-2 experiment. Thirteen SPS-2 projects have been constructed with one additional site under construction. At each site, there are 12 core sections plus various numbers of supplemental sections. The data availability and completeness for the SPS-2 experiment are good overall. A high percentage of the SPS-2 data are at level E--greater than 82% for all data types, and greater than 99% for many. However, a significant amount of data are still missing, especially traffic, distress and faulting surveys, and key materials testing data. These deficiencies need to be addressed before a comprehensive analysis of the SPS-2 experiment is conducted. Required experimental pavement design factors and site conditions were compared with the actual constructed values. Most SPS-2 sections follow the experiment design for the large majority of the design factors. When comparing designed versus constructed, eight SPS-2 projects can be characterized as good to excellent, four projects are considered poor to fair, and one new SPS-2 project does not yet have enough data in the IMS database to be evaluated. The evaluation has shown that several problems may limit the results that can be obtained from the SPS-2 experiments if not rectified. Specifically, no SPS-2 projects were built on certain subgrade types and in some climates. Some SPS-2 sites had construction deviations, and significant materials data and traffic data are missing from other sites or sections. One site has excessive early cracking that will limit its usefulness. However, even though the SPS-2 sections are relatively young (oldest project is 7.5 years) and a large majority show no or little distress, some interesting and important early trends have already been identified that will be very useful to the design and construction of JPCP. As time and traffic loadings accumulate, much more valuable performance data will be obtained. The Federal Highway Administration is conducting a concerted effort to obtain missing data. Recommendations for future analyses are provided in the last chapter of this report. Valuable information will be obtained from this experiment if these studies are carried out.


  • English

Media Info

  • Media Type: Web
  • Edition: Draft Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 203p

Subject/Index Terms

Filing Info

  • Accession Number: 01001246
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-RD-01-167
  • Contract Numbers: DTFH61-96-C-00003
  • Files: NTL, TRIS, USDOT
  • Created Date: Jun 23 2005 11:27AM