What is the function of expansion joints around a slab?

The function of expansion joints around a slab is primarily to allow movement of the slab. Expansion joints are crucial in construction because they accommodate the natural expansion and contraction of materials due to temperature fluctuations, humidity changes, and other environmental factors. Concrete slabs can experience significant changes in size due to thermal stresses; therefore, introducing these joints helps prevent cracking and structural failures.

By providing a designated space for movement, expansion joints reduce the build-up of stress in the concrete, which can occur if the slab is rigidly connected to adjacent elements. This feature helps maintain the integrity and longevity of the structure, allowing it to respond flexibly to physical forces. Understanding this function is essential for anyone involved in planning or creating structures where concrete slabs are utilized.