What is the purpose of joint spacing in concrete slabs?

The purpose of joint spacing in concrete slabs is fundamentally about accommodating the natural movements that occur due to temperature changes. Concrete expands when heated and contracts when cooled. Without appropriate joint spacing, this movement can cause cracks in the slab, leading to structural damage and decreased longevity of the concrete.

By incorporating joints at specified intervals, the slab is effectively segmented, allowing different sections to expand and contract independently without causing stress to the entire surface. This design approach helps maintain the integrity of the concrete structure and minimizes repair needs over time.

While other options may seem relevant, they do not directly address the critical function of joint spacing in maintaining the structural performance of concrete slabs under varying thermal conditions.