Architectural Concrete
We’ve worked with a lot of concrete over the years, but rarely have we poured as much of it as we did on a recent project in Washington Park. The concrete you see on this project is known as “architectural concrete,” to distinguish it as a finished surface from the more utilitarian kind. Architectural concrete is every bit as strong and functional as standard concrete, it just looks better.
Building with custom concrete is a team effort, involving design input from the architect and engineer, detail work from the concrete subcontractor and the careful attention of a Schultz Miller project manager. For this job, concrete subcontractor Central Cascade Concrete worked with the project manager and the concrete batch plant to develop a concrete that had specific appearance and flow plasticity characteristics. Using select pea gravel, fly-ash, a polymer admix, and color pigment, this custom mix produced a bright concrete with a warmer hue rather than the more usual blue-grey mix. The concrete is “board formed,” which means individual boards were used to hold and shape the mix as it cured, rather than the standard sheet forms. The boards for this project were fairly wide, at 12 in., and set tight, so just a little concrete seeped through, leaving a very light line. Sometimes boards are used to impart their wood grain to the concrete, but in this case, resin-faced boards were used to achieve a very smooth finish.
Architectural concrete is time-consuming and labor intensive, so it costs more. And board forms are more expensive than standard forms because they can only be used once. But the result is stunning, and the beauty is long lasting.