Delamination Delamination is the separation of one layer of concrete from another, creating a detached or hollow surface layer. The defect may remain hidden until the surface begins to break away.
Delamination often occurs when finishing operations trap air or water beneath the concrete surface before it hardens. As traffic and weather act on the slab, the upper layer may loosen and eventually spall. Repairs typically involve removing the unsound concrete and restoring the affected area.
Frequently Asked Questions About Delamination
What is delamination in concrete?
Separation of one layer of concrete from another, leaving a detached or hollow surface layer.
How does it happen?
Finishing operations seal the surface too early, trapping air or bleed water beneath it before the concrete hardens.
How is it detected?
Often by sound. Tapping or dragging a chain over the surface produces a hollow tone over delaminated areas before any visible break.
How is it repaired?
By removing the unsound concrete down to solid material and restoring the area, since the loose layer will eventually break away under traffic.