Expansion joint

An expansion joint is a deliberate gap or flexible connection in a structure that accommodates movement caused by temperature changes, moisture, or settlement.

Thermal expansion: The increase in a material’s dimensions as its temperature rises. Temperature-driven growth is a main movement that expansion joints must accommodate.
Coefficient of thermal expansion: A measure of how much a material’s dimensions change per degree of temperature change. This property helps estimate how far adjoining structural sections will move.
Building facade: The exterior face of a building, including its walls, windows, and attached cladding. Facade joints accommodate movement between cladding panels and the supporting structure.
Control joint: A weakened plane in concrete intended to guide cracking to a chosen location. Unlike an expansion joint, it usually manages shrinkage cracking without creating a full separation.
Finger joint (bridge): A bridge expansion joint with interlocking steel plates shaped like fingers across the gap. Its interlocking plates support traffic across a wide movement gap.
Movement joint: A discontinuity in a structure designed to permit relative movement between its parts. Expansion joints belong to this broader family of movement-accommodating discontinuities.
Concrete shrinkage: The reduction in concrete volume as it dries or undergoes chemical changes during hardening. Shrinkage can pull concrete sections apart or cause cracking near restrained joints.
Concrete pavement: A road or paved surface whose principal structural layer is concrete. Pavement joints manage slab movement and help control where cracking occurs.
Construction joint: A planned interface where concrete placement stops and later resumes. Its primary purpose is staged construction, not accommodating substantial movement.
Modular expansion joint: A bridge joint using multiple support bars and seals to span large gaps and movements. Modular systems handle movements beyond the capacity of simpler joint designs.

Linked from 5 pages