EVALUATION OF PRESSURE RELIEF JOINT INSTALLATIONS

Pressure relief joints are used to reduce compressive stresses in concrete pavements and thereby to reduce pressure-related damage. In recent years, their use has become so commonplace that they are frequently overused or used inappropriately. To evaluate the effectiveness of pressure relief joints, representative pressure relief joint installations around the United States were reviewed to identify, define, and document the criteria for the use of these joints. These installations included several climatic zones, placement in both short- and long-jointed concrete pavements, relief joints that were placed prior to overlay, wide joints filled with asphalt concrete, narrow joints filled with foam, and other factors of interest. It was determined that the use of pressure relief joints was often unwarranted and that good contraction joint maintenance programs would have prevented the development of pressure-related problems. The unnecessary or excessive use of pressure relief joints was found to cause damage that was more costly to repair than the damage that would have resulted without the relief joints. Where appropriate, pressure relief joints were found to close rapidly during their first year and to be effective in preventing pressure damage for 3 to 7 years.