Expansion Dams/Deck Joint Systems-Closed Cell Foam Technology for Armorless Joints

Joints must be properly designed and installed to insure the integrity and serviceability. Bridges, approaches, highway pavements, airstrips, buildings and other structures need joints to handle the expansion and contraction caused by temperature changes, albeit bridge joints have more movements than other types and structures. Bridge and bridge approach joints offers the most challenging conditions for designers. These joints must be designed with long term serviceability in mind with little to no maintenance. These joints are designed taking into account expansion and contraction movements resulting from thermal, rotational and other external forces. Water on these joints creates problems as well as certain chemicals and ultra violent generation. The combination of these factors can contribute to often times increased deterioration in the steel or concrete joints, concrete or asphaltic pavements. Many other factors in the design of the bridge/approach must be considered such as drainage, parapet barriers and location. With the ever increasing cost of maintenance and the time involved with traffic control many states have already started to design Armorless Joint Systems. These types of systems can be designed for longer life, but more importantly from the engineering reality, proper maintenance and rehabilitation of joints. Premature failure of bridge expansion joints can be avoided by adopting a rationalized acceptance criteria based on actual laboratory/field testing of joints. This paper reviews many of the alternatives that may be available.