The bottom concrete slab of this parking garage had many cracks that were between 1/4″ to 1/2″ wide. The cracks were left alone for many years allowing water to drain into them. Overtime the concrete slab started to sink because the water started to erode the sub-base.
To help prevent further erosion, we cleaned out the cracks with a saw blade and then filled them with a flexible sealant.
Stay tuned for more pictures in a couple of weeks of other parking garage repairs. We will next be repairing spalling concrete on the slab-on-grade.