The Interstate 5 Portland cement concrete pavement (PCCP) in King County has been in service for over 40 years, twice its planned design life. As such, I-5 is in need of a rehabilitation/reconstruction effort. This study provides WSDOT (Washington State Department of Transportation) information that will aid decision making about the timing, locations, and type of rehabilitation or reconstruction.
Extensive pavement conditions/distress data provided by WSDOT were summarized, analyzed, and used to develop visual tools to communicate the condition of the I-5 PCCP. The performances of the non-rehabilitated, diamond ground, and the dowel bar retrofit and diamond ground PCCP were summarized and compared. Use of such information shows that about 66 percent of I-5 in King County is in need of rehabilitation or reconstruction. To further illustrate these conditions, Arc GIS was used to map the various distresses/conditions, and the results suggest which sections of I-5 should be addressed early in the rehabilitation/reconstruction process.
A field study assessing the I-5 PCCP was conducted at the same location as a 1986 study, providing a unique opportunity to compare the PCCP conditions over a span of 20 years. The field study showed that the number of cracks had more than doubled, spalling dimensions had increased, and faulting displacements had increased by more than 43 percent.
The report concludes with a broad assessment of expected I-5 conditions and necessary WSDOT actions for five-year increments (0 to 5 years, 5 to 10 years and greater than 10 years).