How To Repair Structural Concrete

On a recent job, we needed to restore a section of structural concrete. This particular job was a repair to an overhead section in a lighting niche in the mechanic’s well at a garage that services school buses. Though it’s not the most usual example, it provided a textbook case on concrete restoration.

Surface prep
The first step was to remove the damaged concrete, using a rotary hammer to chip away the bulk of the loose material and a grinder to take the concrete down to solid material. The goal was to work back to a solid base and to fully expose the existing rebar so we could fully encase it in repair mortar. In addition, we used a grinder to remove the old paint around the repair area. This would help blend in the repair so when the final work is painted, you won’t see where the new concrete meets the existing surface.

Some surface corrosion of the rebar had occurred but not enough to decrease the dimension of the steel to any significant extent. We used a wire brush to clean up the rebar and then painted it with Rust-oleum Green Rebar epoxy paint. It’s important not to get any paint on the surrounding concrete; otherwise, it can interrupt the bond of the new concrete with the old material.

To read the rest of this story from JLC, click here.

Related:The Contractor's Guide to Concrete Block