2. Expansion joints

Expansion joints are devices used to ensure the continuity of traffic flow at a break in the deck. Such joints exist at least at the ends of all deck types.

• When decks are very long, intermediate joints are provided to limit the amplitude of length variations, due to temperature or to delayed effects, in the case of concrete structures (shrinkage, creep), and the intensity of forces transmitted at the head of supports.

  The maximum length of a continuous deck without expansion joints is usually around 500 to 600 m, but this can be increased to 800 or 900 m by using special joints.

• Joints are weak points through which water can penetrate the structure. We limit their number as much as possible, preferring continuous or partially continuous structures. In particular,...