What are control joints designed to do?

Control joints are specifically designed to minimize shrinkage in concrete during the curing process. As concrete dries, it naturally shrinks, which can lead to cracking if the stresses within the material exceed its tensile strength. Control joints are intentionally placed in locations where cracks are most likely to occur. By creating a predetermined path where the concrete can crack, these joints help maintain the integrity of the surface and improve its aesthetic appearance by containing potential cracks within the joint itself rather than allowing them to occur randomly across the slab. This is particularly important in large concrete pours, where temperature changes and moisture loss can cause significant shrinkage and related stresses.