polished concrete vs coatings

[thruthefence]

We are in the early stages of building a corporate aircraft hangar,(about 10,000 sq. ft. ) and are considering one of the "polished & sealed " processes as opposed to epoxy or polyurethane coatings. Cosmetic appearance is important, as well as resistance to staining from oils & hydraulic fluids. Anyone have any experience with polished concrete? Thanks in advance.

 

[TDAA]

I did a museum on time that had some issues with the concrete surface. It appeared to be an issue with a curing compound leaving an uneven finish. The surface was intended to be concrete with no other surface, so the appearance was important.

The action decided on was to grind the concrete surface and polish, to give a terrazzo appearance. I did not get a chance to see the completed floor, but I understand it turned out pretty well. If you think you would plan for this type of surface, check with the concrete supplier and see what choice you may have for aggregate color that would look good exposed.

 

[sdz]

I think you will have to pay close attention to crack control. Normally a concrete floor would be allowed to crack from shrinkage and temperature effects with reinforcing to provide some control, but usually not sufficient to prevent some yielding of reinforcement and opening of cracks. While a polyurethane coating would cover up these cracks they would be visible in a polished surface and might allow fluids to penetrate.

Also they could be unsafe; slippery. Coatings often incorporate grit to improve slip resistance.

 

[epoxybot]

IMHO polished exposed aggregate concrete has greater appeal when there are other physical elements that help to draw one eye to the surface. I think an overall application of such a uninterupted floor area would lose some impact.

Having said that, aircraft hydraulic fluid can be very aggressive. If the coating protecting the polished concrete is compromised you will have to get used to a grease stained driveway.

As coating choices go, I think epoxy + uv resistant polyurethane systems or thermoset acrylic systems are the usual choices. The acrylics can give a more glass-like finish.

Now that I think of it, a polished concrete surface with a clear wet-look seal coat will probably result in a dark glaring look to the concrete. Visability, good light reflectance and uniform light colored opaque surfaces in hangers are important for good visibility during service to aircraft and leaking fluids are altogether less likely to go unnoticed.

 

[kenvlach]

Sealed (only) are slippery when wet (very slippery).
Grit-containing coatings get and stay dirty. Extra maintainance.

Seal & then topcoat with something off-white, chemical resistance, non-slick but gleaming, etc. There's a feature article in Finishing Today mag. on a floor coating used in a NASCAR team's garage, and it mentions the same coating has been used in hangars & car dealerships.

http://www.finishingtodaymag.com/CD...icle/BNP_GUID_9-5-2006_A_10000000000000028190

 

[Zambo]

A dryshake floor hardener with a pigment could be considered. The finish would be powerfloat with a sealer used to finish.

Epoxy coatings are more expensive, but as they are applied after casting the slab better control of the finish can be achieved. If an epoxy is uaed the system will have to be selected bearing in mind any dampness in the slab.