I’m not sure why an aircraft hangar needs a concrete floor so highly polished a man could use it as a shaving mirror, or a woman could apply lipstick, but Landmark Aviation in Asheville, N.C., wanted one, and Syncon Inc., Dearborn, Mich., gave it to them in May 2009.
The project was a new pour. Syncon techs started grinding the 25,000 square-foot floor with 50-grit metals, and took it up to a 3,000 grit resin finish, says Ryan Klacking, president, Syncon Inc., Dearborn, Mich.
You probably already know this, but “metal” and “resin” refer to how the tiny industrial diamonds are bonded to the grinding or polishing pads. Metal bonds hold the diamonds more securely, which cuts the concrete more deeply. So “metals” are used for grinding, much as coarse-grit sandpapers are used in the early stages of wood finishing.
“Resin” bonds let the diamonds jiggle around a little more, for a shallower cut. The techs use resins for polishing, just like finer-grit sandpapers are used in the later stages of wood finishing. The grit-number is also similar to sandpapers, with lower numbers being coarser grits and higher numbers being finer.
They treated the concrete with Consolideck® LS® (lithium-silicate) Hardener/Densifier after polishing with a 200-grit resin. The floor got another dose of hardener/densifier after being polished to 800.
Hardener/densifiers are often used on polishing projects. They convert soft calcium hydroxide, which turns into concrete dust, normally a nusiance, to rock-hard calcium silicate hydrate. The calcium silicate hydrate, the same material that makes concrete hard to begin with, fills the microscopic concrete pores. That the surface denser, and creates more surface area for a faster, higher quality polish.
Contractors increasingly use lithium-silicate hardener-densifiers because of their sustainable properties — both economically sustainable and environmentally. Older hardener-densifiers, such as those using potassium-silicate or sodium-silicate, have to be scrubbed into the floor. what doesn’t penetrate has to be rinsed off with fresh water. Then that rinse water has to be collected and properly disposed of.
Potassium- and sodium-silicate hardener/densifier residue that isn’t rinsed away cures into a hard, insoluble white deposit on the floor.
Lithium-silicates are an advance because they penetrate without scrubbing. Just spray and walk away. Small amounts that don’t penetrate dry into an inert white powder that can be swept up and put in the trash.
Here’s a video of a time-trial pitting a lithium-silicate hardener/densifier against a sodium/silicate.
The floor is protected with Consolideck® SLX100® Oil &Water Repellent, a penetrating protective treatment, which keeps contaminants like fuel and oil from soaking in and staining until they can be cleaned up.
You might think a shine this intense would be difficult to sustain (I would), especially in the harsh inudstrial environment of an aircraft hangar. But Ryan re-visited the site in January, and said it had maintained shine and cleanliness remarkably well, despite utility-vehicle, aircraft and foot traffic.
Anyway, I really liked that photo and wanted to share it. Ryan’s brother, Chris Klacking, took it. Good job Chris!