When a major Midwestern food processor wanted to increase the thickness of an existing 4-inch-thick freezer-warehouse floor to at least 5 inches to carry additional storage loads, the concrete contractor opted to use a bonded overlay rather than full-depth floor replacement. The overlay was faster to install and provided the durable, long-term performance that was required at a lower cost.
Achieving a strong overlay bond to the existing floor was especially critical on this project because the facility is maintained at temperatures below freezing, which puts additional stress on the bond line. Techniques used included shotblasting and scarifying of the floor surface, the addition of steel fibers to the concrete mix to minimize cracking, and application of a sand-cement grout to improve overlay bond. To maintain the proper bond and reduce reflective cracking, joint type and location in the original floor were precisely matched in the overlay.