Expansion Joined Work

In building construction, an expansion joint is a mid-structure separation designed to relieve stress on building materials caused by building movement. Building movement at expansion joints is primarily induced by: thermal expansion and contraction caused by temperature changes. sway caused by wind. seismic events

Expansion is the increase in the size of an object on heating. Contraction is the decrease in the size of an object on cooling. Example: Rise in level of mercury in mercury thermometer, on touching a hot object. Example: Lowering the level of mercury in mercury thermometer, on removing from a hot object.

A concrete expansion joint is a small gap that provides space for the concrete to expand and contract. It is placed between the concrete and whatever the concrete abuts, allowing independent movement between these structures. Expansion joints also absorb vibrations and permit soil movement as a result of earthquakes.