Concrete Aggregate:

Decorative concrete contractors discarded descriptions of concrete as dull, gray and utilitarian a long time ago, producing a dizzying number of colors and designs.

What some contractors may not have considered is producing unusual colors using colored aggregate - either as part of the concrete mix or through various exposed-aggregate techniques. A soft champagne pink? Glittery blue? Bright white? All these colors, and more, are possible by taking advantage of the various shapes, colors and characteristics of aggregate unique to different parts of the country.

When working with exposed aggregate concrete, contractors can use a standard concrete mix or find special aggregate with unusual colors or shapes. It can be broadcast on the surface of the concrete, but the trick is to make sure it's installed to the right depth and that it's scattered evenly. If it's not deep enough, the aggregate can break loose from the slab; too deep, and too little is exposed.

Exposed colored aggregate can make the difference between boring and brilliant concrete. Bart Sacco's Concrete Texturing Tool & Supply, located inside a newly built, gated castle in Throop, Penn., near Scranton, shows the range of possibilities available with aggregate. On one floor, Sacco used a concrete mix from Masters Ready Mix Concrete that contained a local blue aggregate, cured it for 28 days under burlap, and a few days later, ground and polished it. "When I poured the floor, I also put glass in it to bring another dimension to it," Sacco says. White and black pigments and chopped mirror were also used. "It looks dynamite," he says.