Experimental Investigation of the Longitudinal Movements Associated With Highway Bridge Joints.

Abstract

Bridge deck expansion joint systems often develop serious problems requiring extensive and expensive maintenance. This has become a nuisance to users and to bridge engineers, and many states have been involved in investigations aiming to alleviate this problem. Results reported by various states regarding the behavior of specific joint sealing systems have been contradictory, indicating that the problems may not be inherent with the particular system. Rather, the problems may stem from a failure to properly assess the actual joint movements, inadequate design criteria, improper installation procedures or other factors such as differences in environmental conditions. In recognition of these problems, a comprehensive experimental investigation of bridge expansion joint movements was undertaken. The longitudinal across-the-expansion-joint movements of a newly constructed bridge in central Louisiana were experimentally evaluated. Since thermally induced movements comprise the bulk of the longitudinal deformations, the temperature characteristics of the bridge sections were also investigated. The movements of the supporting bents and their effects on joint movements were also studied. The bridge was instrumented to assess both short-term and long-term longitudinal movements. The recorded data were analyzed and used to determine whether the joints have been adequately designed to accommodate movements.