We're doing some remodeling of a hospital building that includes installing new floor coverings. The floor slab is a lightweight concrete placed over metal deck forms. Evidently, when the concrete was placed, the top surface froze and was patched. Then it was covered with a rubber flooring. We're removing the rubber flooring now and the patches are coming up with it. The patches range from 1/16 to 1/4 inch thick. What products can be used to patch the floor again and make a longer lasting patch?
Choosing the best repair material requires knowing whether the floor will be covered or exposed. If you're going to put down new rubber covering, tile, or carpeting, you could probably use a flowable topping that's either cement based or gypsum based. These are underlayment materials that can be pumped into place and are nearly self-leveling. If the repaired floor won't be covered and will be exposed to hard-wheel traffic from carts, you might try a higher strength, flowable, cementitious underlayment or a polymer repair material.