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Decorative Concrete Offers Beauty and Benefits
Architects and designers enjoy unlimited choices for aesthetic enhancement
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| Exqusite detailing spices up the esterior of Burdine's
in Aventura, Fla. The precast panels manufactured by Coreslab and
designed by architect Cooper Cary of Atlanta mad use of form liners
from Scott System. Photo courtesy of Scott System. |
Concrete doesn’t just create sustainable structures—it makes
buildings beautiful, memorable, and award winning. Decorative concrete
applications bring all the benefits of regular concrete while adding to
a structure’s aesthetic appeal. For example, exposed, textured concrete
on the interior of a building can help earn a LEED Innovation Credit.
Floors made with white cement look sparkling clean and increase reflectivity,
reducing lighting costs and eliminating damage-prone floor coverings.
Green roofs can be constructed with decorative concrete pavers that add
style and substance. Concrete used in landscaping helps reduce the urban
heat island effect.
There is a decorative concrete solution for almost every sustainable
application, and new techniques are developing every day. Architects,
designers and builders are limited only by their imagination.
Colored Concrete
To many people, the words “decorative concrete” are synonymous
with “colored concrete.” Incorporating color is one of the
easiest ways to create a unique concrete application. There are three
main techniques for incorporating color: integration, staining and dry-shake
color hardeners.
Adding pigments or coloring agents during the concrete mixing process
creates integral color, which produces a consistent tone throughout the
finished concrete. This technique has become very popular in recent years,
says Jamie Farny, PCA’s program manager for masonry and special
products. “Advances in computer controls help in mixing, creating
consistent quality control in batching systems,” he says. To create
diffuse and varied natural tones, many finishers apply one or more concrete
stains, sometimes on top of colored concrete. Stains react with each concrete
surface to create one-of-a-kind effects. To create more intense hues,
dry-shake color hardeners often are applied to the surface of wet concrete
to create an opaque color layer. This technique lends itself to creating
eye-catching designs while increasing the durability of the finished surface.
White Cement
White cement concrete is ideally suited for creating dramatic surfaces.
Made with white cement, sand and aggregates, this concrete offers a crisp,
clean aesthetic. White cement concrete can also be infused with color
to produce almost any color in the rainbow, or matched to materials of
existing buildings when used in rehabilitation or expansion projects.
Floors placed with white cement concrete have a fresh, clean look, and
are easy to maintain. They also offer a high degree of reflectivity, decreasing
the need for artificial light fixtures and lowering energy costs for businesses.
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Exposed Aggregate and Other Textures
Incorporating textures is a cost-effective way to enhance concrete. Using
any of a variety of methods, finishers remove the top layer of concrete
paste, revealing the aggregate surfaces to create a natural aesthetic.
The technique remains popular, Farny says, because it offers a wide range
of textures and an unlimited color selection.
Decorative concrete finishers have a wide variety of other textures at
their command, created with tools like brooms, trowels, rakes, sponges,
rock salt—you name it, finishers are using it to devise innovative
textures.Many companies offer stencils and stamps, which can be used to
create an unlimited array of patterns and textures. Even more aesthetic
options are created with saw cutting and scoring of hardened concrete.
Form Liners
Another method for creating decorative surfaces uses form liners, plastic
or urethane molds that shape concrete inside formwork. Used in precast
and cast-in-place applications, the liners can turn otherwise regular
concrete into artistic masterpieces, while saving materials and costs
through reuse.
With form liners, the possibilities are endless. For instance, Denver-based
manufacturer Scott System offers standard textures like stone, wood and
block; the company also has artistic forms depicting natural scenes, animals
and industry. Dana Scott, director of marketing for Scott System, says
the company’s most popular textures emulate natural stone surfaces.
But its specialty is custom forms, created to the specifications of individual
projects. Projects created with the company’s liners have won awards
across the country.
Increased interest in the method has led to evolutions in liner materials,
says Farny: “There are some form liners available today that, if
properly taken care of, are almost indestructible.” In fact, Scott
says their urethaneforms are guaranteed for 100 uses.
One of the newest evolutions in the technique is brick inlay systems,
which use liners to cast thin (usually ½-in) bricks into the concrete
surface. Using brick inlays, designers can create the appearance of traditional
masonry even when constructing with precast or tilt-up panels.
Architectural Precast Panels
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| Precast by Stresscon of Colorado Springs, this panel
incorporates of of scott System's most popular flagstone textures.
Photo courtesy of Scott System. |
Commonly used in office buildings, banks and hotels, architectural precast
panels can be used as both an aesthetic skin and as a structural element.
“With a precast panel, you might have a piece that acts as a weather
barrier and includes insulation,” Farny explains. “You can
fasten the panel to the structural frame, and it will resist loads while
functioning as cladding for the exterior.” Highly controlled manufacturing
settings mean that precast panels can be fine-tuned to meet an architect’s
specifications with consistent quality. Panels also create a solid building
envelope for excellent thermal performance.
Masonry
Concrete masonry units (CMUs) are another decorative option for designers.
Like concrete, CMUs can help earn multiple points toward LEED Credits,
and CMUs often incorporate recycled materials. But masonry’s real
beauty is in its flexibility and variety: CMUs come in hundreds of styles
and colors, and can be used to create dramatic effects for facades, landscaping
and more. Colored mortars create an even greater variety of creative options.
Self-consolidating Concrete
One of the newest developments in decorative applications is the use of
self-consolidating (or self-compacting) concrete (SCC). “Whether
pigmented or left plain, it has a nice off-the-form finish that can be
cost-effective due to savings in placing and finishing the concrete,”
says Farny. The precast industry has embraced SCC because it reduces noise
normally associated with consolidating concrete into forms, and achieveshighly
consistent finish. Though it can be done in the field, SCC is especially
suited for use in a controlled setting. And for more detailed work, the
material performs well with intricate forms, flowing and consolidating
under its own weight to fill small voids.
Reflective
Floors Light Up Supermarket Chain WinCo Foods uses concrete floors
with white cement to increase daylighting, durability On
the West Coast, a supermarket chain known for value, innovation
and creating upscale shopping experiences is raising the bar even
higher by making its stores more sustainable. Boise, Idaho-based
WinCo Foods is installing concrete floors made with white cement
in all of its new locations, almost 20 in all by the end of 2004.
Reflective concrete floors are created by using white cement, and
white fine and coarse aggregates. The reflective floors bounce light
from both artificial and natural sources, reducing the number of
necessary light fixtures—and the energy used to power them.
In many of the WinCo stores, a skylight system increases natural
illumination, further reducing lighting costs and creating a warm
atmosphere. The result is a clean aesthetic, one that customers
are drawn to.
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| Made with white cement concrete for Lehigh
Cement Co. (Allentown, Pa.) floors in this WinCo supermarket
provide a fresh, clean aesthetic, and lower energy costs by
increasing reflectivity. Photo by King Studios, Boise, Idaho. |
That’s important for the company, whose stores must be warehouse-like
in design to accommodate bulk items, but also inviting to customers
seeking out high-end products. “They work very hard to overcome
a warehouse feeling,” says Larry Rowland, LEED-AP and technical
sales representative for Lehigh White Cement. The combination of daylighting
and glossy, clean floors “creates a fresh, welcoming experience”
for the customer, he says.
The floors also are durable enough to support the weight of small
forklifts, which load stock onto shelves at night. Rowland says
the store cuts costs by not using traditional linoleum floor coverings,
which would have to be replaced frequently. “This is a very
green building technique. You’re not putting another product
on top of that concrete; you’re not harvesting more materials
and using adhesives,” he says.
“These are 30-, 40-, even 100-year floors,” Rowland
continues. “Over a long period of time, they can go back,
grind and polish them, and they will look like terrazzo. They’re
going to look as pretty as they did on the day they opened the stores.”
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