The importance of effectively sealed expansion joints in all types of structures has been recognized for a long time. Bridges, buildings, dams, water/sewage treatment facilities, etc., require weatherproofing expansion joints. This task has become even more difficult, particularly in buildings, with the incorporation of seismic considerations and the increased awareness of "life safety" with regard to pyrogenics. In the event of fire, the expansion joints are primary candidates for the rapid spread of fire and toxic/noxious fumes. Protection is of particular importance in hospital/medical facilities and high-rise structures. The need not only to confine the fire to the point of origin, but to inhibit the spread of fumes, is most crucial. It is estimated that 80 to 90 percent of fire victims succumb to inhalation of smoke/noxious/toxic gases well before the flames reach them. In those cases where the heat and flames reach the victims, the first signs of incapacitation result from toxic fumes. The major North American manufacturers of expansion joint sealing systems are developing composite fire resistive/weatherproof expansion joint sealing systems incorporating a noxious fume barrier that will resist the impact of the "hose stream" from fire-fighting equipment.

Despite all of the progress made to date in concrete technology, there is still no reliable means of preventing local voids or cracks in concrete under site conditions. If concrete structures are required to be waterproof, it is always mandatory to provid

In past decades, several types of bridge joints have been installed in Belgian bridge decks. These joint types behave very differently in time, and the lifetime of a bridge joint is determined by numerous interacting factors. Because of the increasing maintenance costs and the difficulties encountered during the repair of these vulnerable structures, a research project on bridge joints was started in 1980 at the Belgian Road Research Center. The objectives of this research are the basis of the present article. These objectives were originally based on the results of visual inspections of bridges, and they have been continuously modified during the past five years. The following topics are addressed: the relationship between the roughness of the road in the vicinity of the joint and the resulting dynamic amplification of traffic load; the movements (both horizontal and vertical) produced at the joint by heavy trucks; the determination of stresses in the anchorage of expansion joints and buried joints by means of computer programs and model studies; the calculation of the lifetime of buried joints by combining displacement spectra resulting from the deformation of the bridge, the Wholer curve of the mix constituting the joint, and the particular stress distribution in the joint; and the application of research results in practice.

Though a tiny dot on the map of the world, Hong Kong has one of the highest and fastest growing vehicle densities in the world. There are only 1280 km of roads in this city, but vehicles number more than 300,000. Consequently, the roads are severely congested and, in spite of traffic management schemes of traffic light signals and one-way streets, many locations are so jammed that grade separation has had to be introduced by means of flyovers, elevated highways, and similar structures. Such structures inevitably incorporate many movement joints that have proven in practice to be more troublesome than any other components. The problems experienced with movement joints led to careful scrutiny of movement-joint performance and to a series of different joint installations being made for the purposes of comparison, with the object of providing information for the design, construction, and maintenance of future joint installations. This paper describes the types of joints used in Hong Kong, including their performance, and makes recommendations for specifying movement joints.

The principal cause of deterioration to the superstructure and substructure are the expansion joint systems. Bridge engineers and maintenance personnel have long advocated longer spans with fewer and maintenance-free expansion joints. With longer spans, expansion joints have become greater. In 1978, the New York State Department of Transportation invited manufacturers of six different types of modular expansion systems to install their devices on a new structure crossing the Hudson River at Troy, N.Y. This paper is an up-to-date condition survey of the performance conducted on a regular basis of the six different modular expansion joints.