RE: Lafarge (LAF) I never realized that concrete was this hot:
Recasting Concrete
The Drab Stuff of Sidewalks Takes On Hues, Translucence, Intriguing Building Designers
By RAY A. SMITH Staff Reporter of THE WALL STREET JOURNAL
July 21, 2004; Page B1
Colorful concrete?
It's happening -- among other places in Hillsborough, N.C., where Meg Perry started a decorative-concrete business last year after attending a seminar at the 2003 World of Concrete Convention. Ms. Perry, a 42-year-old former homemaker and onetime horse trainer, stains concrete floors, patios, pool decks and sidewalks different colors, resulting in what she describes as an almost marble or stone finish. "The reaction we want is: 'Oh my God, that's concrete?' " she says.
Ms. Perry is one among a loosely knit cast of inventors, architects, companies and entrepreneurs trying to recast concrete -- the humdrum stuff of sidewalks, roads and utilitarian structures -- as an exciting material with endless decorative and structural possibilities. There is even translucent concrete -- concrete embedded with plastic or glass fibers that transmit light from one side of a wall to another.
"Concrete had been taken for granted at some level," says David Shepherd, director of sustainable development for the Portland Cement Association, a trade group based in Skokie, Ill., representing about 49 cement companies in the U.S. and Canada. "There's this new artistic sense of what can be done with it."
Designed by LiTraCon of Germany, this concrete wall owes its translucence to embedded glass fibers. The company says its product is strong enough to be used to construct buildings.
Over the past two decades, there have been a number of efforts to push the possibilities of concrete aesthetically -- from the embracing of concrete floors and countertops in homes to concrete staining, stamping and stenciling. (For those mixing their own concrete, the basic ingredients are cement, sand, aggregate -- usually gravel or crushed stone -- and water. Cement is the binding agent, essentially the glue, in concrete.)
At first, the concrete craze was confined to retailers, avant-garde architects and ultra-trendy individuals, mostly in California. Lately, it's gone mainstream. Elaborate designs and patterns are increasingly being incorporated into driveways, entryways, and pool decks of homes, in states such as Georgia, North Carolina and Texas.
Jill Hesterlee, a 34-year-old homemaker, was convinced concrete would be right at home in her family's five-bedroom, six-bath home in Carrollton, Ga., after falling in love with a countertop she saw while shopping in an Anthropologie clothing store in a local mall. "I asked the manager what it was and found out it was concrete," she says. She hired Decorative Concrete Institute of Douglasville, Ga., to have the kitchen and bathroom countertops, the back splash behind the stove, the floors, front porch, and veranda near the pool done up in decorative concrete. At first, she says, "my husband was a little skeptical of the idea, but he is really pleased with it also."
Concrete is even getting more respect in people's homes on a functional level as well as a decorative one. Insulated concrete, which is said to keep air from leaking better than wood, thus reducing air-conditioning and heating bills, has gained popularity. In fact, concrete homes, including ones that have insulating concrete forms, represented an estimated 16% share of new-home construction in 2003, compared with 3% in 1993, according to the Portland Cement Association.
On a larger level, post 9/11 national-security concerns have prompted growing use of the material in the form of concrete cores, to enhance stiffness in buildings, notes Richard L. Tomasetti, co-chairman of New York-based engineering firm Thornton-Tomasetti Group. Design plans for a major building at Ground Zero on the site of the destroyed 7 World Trade Center call for using reinforced concrete to surround the building's core, which contains stairs, elevators and antennas for emergency communication.
Kennedy & Violich Architecture Ltd. of Boston is testing "smart" concrete, which has embedded sensors so that sidewalks and highways, for example, would light up in dim situations. "It could increase safety," says Sheila Kennedy, a principal at the firm.
The momentum building around the material is in evidence at the National Building Museum's eight-month-long exhibition/celebration of concrete called "Liquid Stone: New Architecture in Concrete." On display at the museum in Washington, D.C., are 29 architectural projects that use concrete -- a material believed to have been first used more than 2,000 years ago -- in what the museum says are "exciting" ways.
The exhibition, which opened last month, is sponsored by Lafarge, a manufacturer of building materials. Among displays generating the most buzz is a small-scale model of a chapel with translucent-concrete walls; the walls contain embedded plastic fibers that transmit light from one face to the other. The chapel "shows that something so historically inert can become light," says Bill Price, a 38-year-old architect from Houston, whose company designed the chapel. Beaming, he adds: "Concreteness is not so concrete."
The show also features a series of translucent-concrete panels developed by Will Wittig, an assistant professor at the University of Detroit Mercy. The panels are a tenth of an inch thick, which is thin enough to be translucent under direct light. The panels are made of Portland cement and sand, reinforced with a small amount of chopped fiberglass.
While translucent concrete has been attracting attention, it is also prompting skepticism as a viable building material. "There's no way a building is going to be built with it," scoffs Kenneth A. Hiller, a senior vice president and chief structural engineer at construction giant Bovis Lend Lease, a division of Australian real-estate services company Lend Lease Group. He says he can't envision anyone using translucent concrete to hold up loads. If it is used in a building, he says, it would be "purely for artistic reasons."
Christian Meyer, a professor of civil engineering at Columbia University, also wonders about the practicality of see-through concrete. "Strength isn't the first thing that comes to mind when you talk about translucent concrete," says Prof. Meyer, who developed a concrete that incorporates crushed glass and is being used in floor tiles and other products made by Wausau Tile Inc. Translucent concrete "is probably more for interior decorating," he says. "I can't imagine you would use it to build an 80-story building."
Mr. Wittig says he never intended his material for structural use and saw it more as a "poetic gesture." But Mr. Price says his product is thick enough to be used to construct buildings. "Absolutely," he says, citing the chapel. "It's structural and decorative." Translucent walls he designed were installed earlier this year in a boutique in Korea. He says he has a licensing agreement with an Austrian concrete manufacturer for the material, a deal that includes building the company's headquarters with translucent concrete.
Also on display at the exhibition is a 5-foot-high concrete wall designed by LiTraCon GmbH, of Aachen, Germany, that transmits light via embedded glass fibers. LiTraCon says that its product is strong enough to be used to construct buildings, but that doing so would be too expensive because of the glass fiber.
online.wsj.com |
