Ekspansjonsjoint

Ekspansjonsjoint, also known as an expansion joint or movement joint, is a structural discontinuity or gap designed into a building, bridge, or other structure to allow for controlled movement. This movement can be caused by a variety of factors, including thermal expansion and contraction due to temperature changes, moisture variations, seismic activity, or mechanical loads. Without these joints, the stresses generated by these movements could lead to cracking, buckling, or even structural failure.

The primary function of an expansion joint is to absorb and accommodate these dimensional changes without compromising the integrity of the structure. They essentially provide a safe space for the material to expand into or contract away from, preventing the build-up of excessive forces. The design and spacing of expansion joints depend on the specific material, the expected range of movement, and the environmental conditions.

Common materials used in expansion joints include rubber, metal, or specialized polymers. These materials are chosen for their flexibility, durability, and ability to withstand the expected stresses and environmental exposures. The visible part of an expansion joint in a walkway or bridge deck is often covered by a flexible sealant or a metal cover plate to maintain a continuous surface and prevent water or debris from entering the joint. In larger structures like bridges, the expansion joints can be quite complex, incorporating interlocking metal finger plates or modular systems to accommodate significant movement while maintaining a smooth passage for traffic.