The word concrete evokes the plain, cold, gray floors often found in factories and garages. But it's more than that.

"Concrete might be considered unimaginative as a flooring choice without coloring, texture, patinas and the mottled natural finishes that many people are unaware of," says Stephen Riggs, vice president of Phoenix-based Progressive Concrete Works.

"But to sculpt, score, do various patterns and do colored areas next to each other in rhythmic patterns - then you start to see interest and eye movement. Concrete goes from something very cold to something warm and inviting," says Riggs, a licensee of Madera, Calif.-based Bomanite Corp., which has licensees in 67 countries around the world. Progressive Concrete recently put concrete flooring in six entranceways and two theme courts at Arizona Mills in Tempe, Ariz.

At the mall, one of the theme courts installed by Riggs' company was the Tree Court. To create a floor that would give the look of an old, organic, mossy rock surface, a green-color hardener made by Scofield (the only other brand Bomanite licensees are authorized to use) was applied to wet concrete. A brown-chemical stain was then "fogged on with a highly atomized spray for almost an air-brush effect, so there were brown specs on top of the green patina, thousands upon thousands of tiny specs that gave it the mossy rock look," says Riggs.

In other sections of the mall, creative color combinations were used in conjunction with different imprinting patterns - for instance, Bomanite's 12" hexagon tile and its running-bond brick patterns, stained with green over a gray base.

In addition, Scofield chemical stains were applied over that company's dust-on color hardeners in combinations such as auburn over white, turquoise over blue, ebony on black, green on gray and bronze on pink. The stain makes a variegated, mottled color. No two ever turn out quite the same," Riggs says, "and you get great illusions of depth that look very natural."

Making concrete better In an effort to show how warm and inviting concrete could be, Bomanite began stressing to designers and architects that concrete offered nearlylimitless possibilities when customizing commercial areas such as restaurants, h otel lobbies, office buildings and shopping centers.

One developer that heeded the call to concrete was The Mills Corp., Arlington, Va. Designers for other Mills shopping centers, including Grapevine Mills and Ontario Mills, are among those using concrete flooring to create excitement and personalized design motifs in new centers.

To aid designers, Bomanite developed a systems approach, called Patene Artectura, that offers stain and patterning options for concrete floors. Kellie Romero, Bomanite communications director, notes, "Designers may want to do something they weren't aware they could do with concrete - for instance, trying to create excitement in entertainment areas of shopping malls."

While the process of staining and patterning has striking effects when used in new installations, it also is effective in renovating existing flooring. Chemical staining, saw-cutting and sandblasting are ways of giving new life to existing concrete, says Christopher Stewart, Bomanite director of technical services.

"These techniques lend themselves to use on older concrete that is stressed or simply plain," he says. "There's a lot of renovation going on at shopping centers. For instance, a center may have carpeting that's worn. They'll take out the carpeting and apply these techniques to the concrete subfloor."

The saw-cutting technique, he explains, involves special saws designed to go into concrete at 1/4" depths and 1/8" to 3/8" variable widths. The cut is grouted with grout of any color, but shades ranging from light gray to dark brown are usually chosen.

Elaborate graphics such as personalized store logos require sandblasting. A special rubber matting with a sticky back is cut to match the logo. The sandblasting technique is often used over stained or imprinted surfaces.

Both sandblasting and saw-cutting techniques have been used successfully by Bomanite of New Jersey, with headquarters in Old Bridge. Ira Goldberg, the company's president, describes work done for Neiman Marcus at Garden State Plaza in Paramus, N.J.

There, the store's logo was etched into an existing concrete slab approximately 20' by 15' just outside the store. A stencil was custom-made with the logo, which is in script, and the design was sandblasted into the slab. A geometric design was etched around the logo with a saw-cutter. Pine, auburn and Caribbean blue Bomanite chemical stains were then applied.

The company also cut an elaborate crown design into an existing concrete floor at the Statue of Liberty Museum Gift Shop using a diamond blade saw-cutter. The spikes were then stained with sea mist and Caribbean blue, while pine, auburn and ebony were used around the spikes. Two coats of Bomanite's Aqua Seal, a water-based sealer, were applied on top of the stain, followed by one to two coats of interior floor finish. The 400' installation won Bomanite's Silver Award for the use of Patene Artectura in 1998.

In addition to the colors used in these projects, Bomanite's line of chemical stains includes seal brown, olive and rust red. These same colors take on different hues when applied over the white or gray bases of existing concrete flooring. They can also be used over floors on which dust-on color hardeners were applied when the concrete was poured.

Maintenance Bomanite puts a high-grade water or solvent-based acrylic sealer over its work. The sealer takes 6 to 8 hours to dry. After this first application, a lighter-bodied acrylic sealer is recommended for regular maintenance to protect the original coating and keep it from wearing through. In between applying maintenance coats of sealer, floors may be polished or burnished as part of the maintenance routine.

"In a busy shopping center, you'd probably want to apply sealer every 30 to 90 days depending on traffic patterns," says Stewart.

While regular maintenance with sealer is important for chemical stain surfaces, other concrete surfaces require less maintenance. "Dust-on hardeners wear like iron, and imprinted surfaces wear exceptionally well," says Riggs. "We've done outdoor work that's stamped, colored with dust-on hardener and isn't maintained with sealer. It still looks great after 27 years."

Bomanite sealer was used at Arizona Mills. "Their sealer is compliant with EPA requirements. If a sealer has too much solvent, it will go into the air," says Riggs.

Discussing maintenance, Stewart says, "For routine cleaning of concrete surfaces, you can use cleaning and buffing machines. It's important to keep the surface free of debris and dirt and to clean with a pH neutral cleaner to avoid a reaction with the sealers."

Affordable yet functional The Patene Artectura approach is practical as well as creative. Its versatility allows it to be used in combination with other types of flooring in shopping centers, such as tile, marble, carpet, hardwood, stone or slate. The concrete flooring just inside the entryways to Arizona Mills serves as a buffer between the outside environment and the hardwood floors of the mall's main concourse.

"Hardwood isn't usually used in shopping centers, but, because the concrete floor was used as a buffer between the outside and the concourse, it became feasible to put in hardwood," says Riggs. The concrete entranceways, which were 40' by 60', served to absorb the harsh exterior desert environment, with its fine silt and sand-dust particles.

The concrete was more resilient to abuse than the hardwood or, for that matter, the carpeting covering other areas of Arizona Mills, he adds.

Concrete flooring offers design possibilities by providing a great deal of color and interest for a lower cost than such materials as marble, slate or imported tile. Riggs also says that the cost of concrete flooring with design systems is comparable to that of domestic tile.

"By using texturing, staining and sealing with lustrous sealers, you can produce a jewel-like, gleaming quality," says Riggs.

Concrete has come a long way since the late '40s and early '50s, when it was the Federal Housing Authority (FHA) standard for home flooring in Arizona. But even then, says Riggs, "the more you waxed and polished this colored concrete, the more it developed a sense of depth. Many younger people are discovering these floors in older homes - since covered with linoleum - and restoring them."

The Patene Artectura approach is helping concrete floors come full circle with a punch that fits perfectly with the modern shopping center's multi-use environment.

In one section of Arizona Mills, for instance, Riggs was asked to place brass stars 8" to 14" wide directly onto the colored concrete between the food court and the movie theater. In another, he created a Rain Court with Pueblo Indian motifs that included geometric configurations and the use of colors such as bronze and pink to resemble pottery.

"Shopping center developers want to create neighborhoods," says Riggs. The creative use of concrete is allowing them to do just that.