We did concrete curb and gutter work for a school parking lot. Concrete was supposed to be air-entrained but it was a long haul to the job and the concrete lost air. We placed it anyway. Now the owner says we have to rip out $5,000 worth of curb and replace it. Are there any alternatives to this? Can't we seal the concrete to protect it from freeze-thaw damage?
Most concrete people believe that sealers won't protect inadequately air-entrained concrete from freeze-thaw damage. However, some manufacturers' tests on non-air-entrained concretes protected by sealers show good resistance to scaling after 285 cycles of freezing and thawing (see Concrete Construction, October 1989, page 900). Why not tell the owner you'll apply a sealer and will guarantee the work against scaling for 5 years? The sealer might prevent damage and will certainly cost a lot less than removing and replacing all the concrete. If the concrete does scale within a few years, you may still be able to repair damaged sections at a lower cost than for removal and replacement. When do you add water?