What is delamination, and how does it affect a concrete deck's performance?

• A. A process where concrete dries out causing shrinkage.
• B. A type of reinforcement failure due to corrosion.
• C. Separation of concrete layers within the slab; reduces structural integrity and load transfer, potentially increasing cracking.
• D. A coating failure that allows water infiltration.

Answer: (C)

Delamination is the separation of concrete layers within a slab, usually between the wearing surface and the underlying structural layer. When these layers aren’t bonded, the deck can’t transfer loads across the interface as a single unit. This loss of bond reduces the deck’s ability to carry and distribute loads, weakening the overall structural integrity and making cracking more likely. The voids created by the separation also allow water to penetrate, which can accelerate freeze–thaw damage and, over time, corrosion of reinforcing steel. In short, delamination compromises load transfer, stiffness, and durability, leading to more cracking, surface deterioration, and longer-term damage if not addressed.