Title: The Effect of PCC Joint Sealing on Total Pavement Performance
Author(s): Steve Shober and Terry Rutkowski
Publication: Symposium Paper
Appears on pages(s): 769-798
Keywords: Joints (junctions); joint sealers; performance; portland cement; sealing.
The Wisconsin Department of Transportation has been studying the effect of PCC joint/crack sealing on total pavement performance for nearly 50 years. The issue has always been very simple: does joint sealing/filling enhance total pavement performance; if so, is it cost-effective; if so, what is the best sealant system. Most research done nationally has focused on the last portion of this issue (the best sealant system) and has totally ignored the primary issue (total pavement performance). In the 1950's and 1960's, Wisconsin engineers noted that the initial filling and refilling of contraction joints had no beneficial effect on total pavement performance. In 1974 a carefully designed joint and sealant study began with sealed joints (which were kept sealed for at least 10 years) and with totally unsealed joints. After 10 years it was concluded that the pavement with unsealed joints had better overall pavement performance (distress, ride, materials integrity) than the pavement with sealed joints. In 1990, after considerably more data verified all the previous findings, Wisconsin passed a policy which eliminated the sealing of PCC pavement joints in new construction and in maintenance. Joints are now sawed 1/8 inch wide during construction and no sealing is ever performed. This has saved Wisconsin at least six-million dollars a year with no loss in pavement quality. This report summarizes ongoing research and verifies that Wisconsin's policy is cost-effective. We believe the burden of proof has now shifted. The challenge, for those who advocate that water and incompressibles must be kept out of the joint, is to prove this position is economically justified. This entire issue must begin to be addressed from a broad perspective so there can be enlightened discussions and so that productive research can pursue.