An Asphalt Plug Joint (APJ) produced by Koch was physically tested in a pilot study sponsored by the Wyoming Department of Transportation at the University of Wyoming. An APJ was built, instrumented, and cycled to simulate 10 years of service for spring, fall, summer and winter conditions. A crack occurred during the winter cycling and was repaired. The joint was then tested until failure. Failure occurred as a joint material separated from the joint edge. The joint motion was concentrated between the bridging plate and the joint end. The APJ material exhibited both visco-elastic behavior and a brittle transition temperature in the operating temperature range. The pilot study is being extended to further investigate the nature of the joint and the material.

It is no secret that many of our existing highway bridges that have been constructed after World War II have become maintenance problems. Flawed assumptions regarding the true performance life of many bridge deck components such as decks, piers, substructures, superstructure, etc. are now very much in evidence. The entry point for much of the deleterious water borne chemical runoff is through the expansion joints. Many of these older structures have deck lengths starting at 20 feet and upwards but the great enemy of bridge deck edges and sub-structural components is the leaking expansion joint. In addition to this many well designed expansion joints just do not have the adequate fastening strength to remain in place under the high speed repetitive truck loadings to which they are now exposed. These jointing systems were conceived and produced in previous years where no real performance data existed for making proper judgements with respect to service life. The fairly recent development of non-metallic expansion jointing systems takes into account knowledge learned regarding true service life of formally popular devices and materials.

For a variety of reasons, one should anticipate that the performance specifications for expansion joints will become increasingly stringent. This paper attempts to consider the design implications of such specifications. The following desirable features and practical means of achieving them are discussed: i) continuous seals that can accommodate severe directional changes at curbs and walls, ii) fully radiused directional changes of the metal and polymeric components, iii) simple replacement procedures, and the ability to accommodate modifications for overlays, iv) fasteners which do not rely on friction to prevent impact or vibration induced slippage between components, and v) no reliance on adhesives for bond between the seal and metal components.

The Wisconsin Department of Transportation has been studying the effect of PCC joint/crack sealing on total pavement performance for nearly 50 years. The issue has always been very simple: does joint sealing/filling enhance total pavement performance; if so, is it cost-effective; if so, what is the best sealant system. Most research done nationally has focused on the last portion of this issue (the best sealant system) and has totally ignored the primary issue (total pavement performance). In the 1950's and 1960's, Wisconsin engineers noted that the initial filling and refilling of contraction joints had no beneficial effect on total pavement performance. In 1974 a carefully designed joint and sealant study began with sealed joints (which were kept sealed for at least 10 years) and with totally unsealed joints. After 10 years it was concluded that the pavement with unsealed joints had better overall pavement performance (distress, ride, materials integrity) than the pavement with sealed joints. In 1990, after considerably more data verified all the previous findings, Wisconsin passed a policy which eliminated the sealing of PCC pavement joints in new construction and in maintenance. Joints are now sawed 1/8 inch wide during construction and no sealing is ever performed. This has saved Wisconsin at least six-million dollars a year with no loss in pavement quality. This report summarizes ongoing research and verifies that Wisconsin's policy is cost-effective. We believe the burden of proof has now shifted. The challenge, for those who advocate that water and incompressibles must be kept out of the joint, is to prove this position is economically justified. This entire issue must begin to be addressed from a broad perspective so there can be enlightened discussions and so that productive research can pursue.

Modular Expansion Joint Systems were first introduced to the bridge designer in late 1960 and early 70's. As more modular systems became available and each design quite different, the engineer must judge the competing claims of the manufacturers. Many of the systems had only been introduced and consequently there was no long term performance history. The New York State Department of Transportation therefore decided, with the support of the FHWA to evaluate the performance of several of these modulars expansion system under identical conditions. The Collar City Bridge, initially known as the Hoosick Street Bridge, carries Rt. 7 across the Hudson River at Troy, New York. This 16-span structure consists of a monolithic concrete deck slab 215mm thick on steel girders. It is 1,033m long and 38.4m wide. Six different types of modular expansion joints were installed in 1980.