Evaluation of the Effectiveness of Pressure Relief Joints in Reinforced Concrete Pavements

About the report:

Reported are studies of the effectiveness of a 4-inch (100 mm) wide compressible material installed at 1,000-ft. (305 m) intervals in a jointed, reinforced concrete pavement in reducing pavement blowups. The studies were made on an Interstate highway carrying some 30,000 vehicles per day, including approximately 7,000 trucks and buses. The study contrasts the behavior of the pavement before these pressure relief joints were installed with that observed afterwards. Brief discussions of the factors indicating the need for such joints, the problems associated with their use, and the potential for their use under overlays are included. The following recommendations are presented. The practice of providing pressure relief joints in pavements having blowup histories or exhibiting blowup tendencies should be continued. The decision to provide pressure relief joints should be made only after due consideration of the pavement design and its performance history. The decision criteria enumerated herein are suggested as guidelines. Pressure relief joints are not recommended within 500 ft. (150 m) of bridge protection expansion joints Type XJ-1 or of full pavement width blowups where pavement stresses have been relieved as evidenced by wide joints near the blowups. Consideration should be given to omitting pressure relief joints at full-depth full-width (all lanes) repairs. This omission should be accompanied by the greater use of relief joints at mid-slab length of blowup prone sections of pavement. Pavements containing pressure relief joints should be inspected periodically for evidence that intermediate joints are opening excessively such that in place preformed seals can no longer be accommodated. Conversely, such inspections may indicate the need for additional relief joints.

Authors