Brutalism is the architectural term perhaps most closely associated with concrete. Stark in nature, dull in color, big-box retail and industrial buildings are more apt to come to mind than more elegant structures.
But in their quest to expand the uses for the material in an architectural context, companies are developing new products and contractors are refining existing techniques to make concrete more versatile and aesthetically pleasing.
The use of coloring, stamping, staining, and polishing has grown in popularity throughout the 1990s to today. These techniques are drawing the attention of building owners and have become part of the designer's pallet. In response, contractors are rushing to add these techniques to their portfolio of services.
Along these same lines, use of tilt-up concrete is growing exponentially. Once relegated to mundane warehouse-type buildings, tilt-up has broken out of the box in which it was once held and is now giving contractors the ability to produce distinctive structures.
Decorative concrete is the fastest-growing segment of the concrete industry, says James D. Engleman, director of the American Society of Concrete Contractors' (ASCC) Decorative Concrete Council. Engleman, who also owns Engleman Construction, Macungie, Pa., says as recently as the early 1990s, decorative concrete only was about 1% of his company's business.
"Five years ago, we were doing about 15 to 20 decorative concrete jobs per year," says Engleman. "Now, we're doing about 80 to 90 jobs per year, and we have a short season."
Tom Ralston, president of Tom Ralston Concrete, Santa Cruz, Calif., says his company has grown 25% a year in each of the past 10 years doing mostly decorative concrete. He cites a recent study by the American Concrete Institute and ASCC as evidence that the trend in decorative concrete is only just beginning.
According to the study, approximately 3 to 4% of all concrete in the U.S. incorporates color. "By 2007, the number will increase two-fold and possibly more," Ralston says. "I believe the trend will continue to get stronger and more popular."
Tilt-up panels at the curved entrance arcade of the Ventana Medical Systems facility, which was completed last January, take on the form of the glass slides manufactured by the company.
"Decorative concrete is no longer a niche market; it's hit mainstream," says Robert P. Harris, director of product training at The Scofield Institute, Douglasville, Ga. "It's the designer's medium of choice."
The industry, in turn, is responding to the market's need for information and training. Because of its popularity, Portland Cement Association and the Chicago-based Precast/Prestressed Concrete Institute (PCI) are revising their guides on the subject.
With a flood of contractors adding decorative concrete to their list of services, the need for training is all the more important. ASCC conducts training across the country. Last year, materials manufacturers L.M. Scofield Co., Douglasville, Ga., together with MasterBuilders Inc., Cleveland, formed The Scofield Institute, which offers workshops for designers and contractors.
Product manufacturers also are responding by developing new products. "The industry is concentrating on three issues in relation to concrete: appearance, cracking, and making it easier to place," says Michael Gee, marketing manager, North America, for Grace Construction Products, Boston. Surface retarder technology, pigments, and self-consolidating concrete are product improvements that Grace has developed.
Decorative concrete is being used on entryways, floors, walls, columns, and beams in more and more commercial applications, such as entertainment venues, commercial retail, and office buildings. Tenant improvements and schools also are growth markets, says Harris.
Techniques have progressed from coloring and stamping to stenciling, staining, and overlays (see related story, page 53). "Overlays and staining are hot areas," says Harris. Ground-polished decorative concrete also is hot." Grocery store chains are opting for colored overlayments and polishing in lieu of terrazzo flooring.
Tilt-up concrete is accomplished by pouring wall panels directly on the floor slab, then tilting them into place after curing. But tilt-up isn't just concrete boxes anymore. With EIFS [exterior insulation finishing systems], decorative details can be glued onto the walls.
Integration of a glass and metal entry softens the look of tilt-up concrete panels at the Lunar Bowl.
Two recently completed commercial projects — the Ventana Medical Systems campus in Tucson, Ariz., and Lunar Bowl bowling center in Blue Springs, Mo. — illustrate the extent to which tilt-up concrete has progressed.
Tilt-up panels mimic the products manufactured at the 182,000-sq.-ft. Ventana Medical Systems campus, providing architectural character to a group of otherwise square industrial boxes.
The tilted concrete panels are 4 ft. taller than the adjacent panels and tilt out every 40-ft.structural bay, says Matthew W. Sears, design principal for HDR's Tucson office. "The result is a wall that steps up and down and in and out without adding area to the building, breaking up the massive look of a large box, and complying with the local building code requirement to break up the wall every 50 ft.," says Sears.
With its space-age appeal, the Lunar Bowl, completed in the fall of 2001, may prove to be one giant step for tilt-up contractors in the Kansas City, Mo., area. Two similar bowling centers constructed previous to the project used a pre-engineered metal building frame and roof system with a masonry block exterior. But local contractor Meyer Bros. Building Co., working on an open-book basis, convinced the owner that tilt-up would be less expensive, faster, and a superior product for the project.
The 39,000-sq.-ft. design-build project was constructed using site-cast tilt-up concrete wall panels, in addition to a conventional structural-steel framing system. "Tilt-up is as easy a material to design with as most other materials," says Don Bozich, principal of Bozich Architects, the project's Kansas City, Kan.-based architect. "You just have to think of tilt-up in that context, and consider how you can use it in different ways."
In this instance, Bozich says that the boxy look of the tilt-up was softened by the integration of the glass cube entrance and the lunar concept of interior designer Tom Nicholas, which was carried out onto the exterior panels.
Building Teams are only beginning to realize the usefulness of decorative and tilt-up concrete. The more the methods are used, the more new materials, techniques, and equipment will be developed to further mainstream their use.