Designed to span gaps between structural elements, expansion joints are necessary to absorb movement, and accommodate shrinkage and creep effects and changes in temperature on reinforced concrete, pre-stressed concrete, and steel structures, and particularly on bridge decks.
Why Are Expansion Joints Necessary?
Expansion joints are essential components of any structure designed to absorb the thermal expansion and contraction of materials caused by changes in temperature. Without them, the stress on the structure caused by the expansion and contraction of the materials can cause serious damage. This is why expansion joints are necessary in many forms, from bridges to buildings and beyond.
When a structure is exposed to extreme temperatures, the materials used in its construction can expand or contract in an unbalanced way. This can cause cracking, warping, and other damage to the structure. Expansion joints are designed to absorb the movement caused by this expansion and contraction, preventing damage that could otherwise occur.
Expansion joints are typically made from flexible materials such as rubber and metal. They are installed between sections of a structure, allowing for movement without stress. This is especially important in longer structures, such as bridges and roads, where the movement caused by thermal expansion and contraction can add up significantly over the length of the design.
In addition to absorbing thermal expansion and contraction, expansion joints can also be designed to absorb vibration. Vibration caused by traffic and other sources can cause fatigue in the material of a structure and can eventually lead to cracks and further damage. Expansion joints are designed to absorb the vibration