Pot Bearings and PTFE Surfaces

This digest provides a summary of the pot bearing synthesis that was performed in Phase III of NCHRP Project 10-20, Elastomeric Bearings Design, Construction, and Materials. Phase III concerned low temperature bearing behavior and prequalifications and acceptance testing. Pot bearings and bearings with PTFE (polytetrafluorethylene) sliding surfaces are widely used in bridge construction. They support heavy compressive loads while permitting large movements or rotations. Despite their wide use, they are typically designed and constructed on a highly empirical foundation based on guidelines proposed by the manufacturer. Present practice in the United States and abroad was examined in some detail. European experience is included because it is frequently longer than that noted in the U.S. The discussion of pot bearings includes structural behavior, design, materials, fabrication and installation, and certification test methods. For PTFE sliding surfaces, the discussion covers applications, material properties, design, installation and fabrication of bearings with PTFE, and certification methods.