What is the primary purpose of joints in flatwork concrete?

The primary purpose of joints in flatwork concrete is to control cracking by allowing for movement. Concrete, as it cures and undergoes temperature changes, expands and contracts. If there are no joints in place, these movements can lead to uncontrolled cracking, which may compromise the integrity and appearance of the concrete surface.

Joints are strategically placed to create predetermined weak points in the concrete, helping to absorb and distribute tensile stresses that arise during curing and under load. By providing space for this movement, joints effectively manage thermal expansion and contraction, minimizing the risk of cracks that could extend across the surface and potentially lead to structural issues.

While joints can have additional functionalities, such as assisting in water drainage or contributing to the overall aesthetic design, their primary role centers on mitigating cracking associated with concrete’s inherent properties.