JOINTLESS BRIDGE DECKS

Deck joints in a bridge are the source of many problems over its lifetime. In time, chances are good the joint will leak, permitting water and salt to leak through. Often this leads to deterioration of the concrete pier cap and superstructure beneath. The solution of Tennessee DOT is to eliminate nearly all bridge deck expansion joints and superstructure expansion bearings. For bridges up to about 400 ft long with steel superstructures, and 800 ft long in concrete, this means no expansion joints even at the abutments (with some exceptions). For bridges longer than this, expansion joints are used but only at the abutments. Tennessee DOT reports almost no problems have resulted from using this approach. A few structural details are given to illustrate how Tennessee designs “integral abutments,” and provides fixed connections of the superstructure to the piers.