What is the purpose of expansion joints in concrete?

The purpose of expansion joints in concrete is to allow for movement due to thermal expansion. Concrete is a material that can expand and contract with changes in temperature. When concrete heats up, it expands, and when it cools down, it contracts. If there are no provisions for this movement, the concrete can crack or become damaged, compromising the integrity of the structure.

Expansion joints are specifically designed to absorb this movement, providing a space that accommodates the thermal expansion and contraction without causing stress that could lead to cracking. This ensures that the concrete remains intact over time, effectively extending the lifespan of the structure and maintaining its appearance and performance. In addition, these joints help to minimize noise and vibrations caused by the movement of the concrete slabs.