Concrete Applications for a Sustainable World
Buildings Home >
Sustainable Design > Concrete
Applications
Building Today to Conserve the Future
by Ryan Puckett
 |
| The PCA's new office is located within the
LEED-certified headquarters building for the National Association
of Realtors. |
Durable, energy efficient and recyclable – a quick evaluation
of concrete applications and it’s easy to determine that this
versatile building material is sustainable. Just how major a role
it will play as the green building movement continues to proliferate
depends on how many are willing to take a closer look.
“We want the green building community to realize all of the
solutions concrete can provide,” said David Shepherd, AIA,
and director of sustainable development for the Portland Cement
Association.
While Shepherd considers concrete’s durability, energy performance
and recyclability to be its strongest green attributes, he stresses
the importance of the application. “It’s how the concrete
is used that has the far greatest impact on environmental performance,”
notes Shepherd.
With proper application, concrete can provide sustainable solutions
for a host of green issues, including: reducing undesirable sound
transmission, increased energy performance, urban heat-island reduction,
locally available materials sourcing, improving indoor air quality,lighting
efficiency, stormwater management and thermal mass. (Visit www.ConcreteThinker.com
for a further explanation of these solutions.)
“It’s an extremely durable product," the first
and foremost sustainable attribute according to Gary Bailey, AIA,
and principal/owner of Innovative Design, Inc. Bailey’s firm
has been focused on sustainable design since 1977. These days, he
favors insulated precast concrete to assist with daylighting and
to average out building temperatures due to concrete’s thermal
mass. “Because of the way heat transfers through concrete,
it acts as a storage element, storing warm air in winter and cool
air in the summer.”
Since concrete does not provide a food source for mold or mildew,
Bailey also counts indoor air quality as another component of concrete
structures in sustainable design. “Look at health issues in
this country, with regards to allergies and asthma—buildings
are a big part of that problem. Concrete mitigates those issues.”
Echoing the sentiment regarding the versatility is Lionel Lemay,
vice president of technical resources for the National Ready-Mixed
Concrete Association. “For instance, look at pervious concrete,”
says Lemay. Beyond its primary benefit of stormwater management,
he points out that pervious concrete allows for more planting of
trees, absorbs noise, potentially decreases the urban heat island
effect, and, it can be recycled.
In fact, concrete was the most recycled material in North America
by weight in 2005, according to a survey by the Construction Materials
Recycling Association (CMRA).
Survey results indicate that recycling companies recovered as much
as 140 millions tons of concrete in 2005. Equally impressive, recycling
plants were able to recycle 99 percent of what they took in.
A Lesson In Reduce, Recycle and Reuse
Just last summer, Recycled Materials Company, Inc., (RMC) of Arvada,
Colo., completed the demolition and removal of 6.5 million tons
of concrete and asphalt aggregates at the former Stapleton International
Airport. With its concrete runways and concourses sprawling throughout
the outskirts of Denver, the project was dubbed the “World’s
Largest Recycling Project.” (With the volume of recycled concrete,
enough material was recycled to construct a two-lane roadway roughly
1,000 miles in length.)
Soon after the airport closed, construction began on a massive mixed-use
development of commercial buildings, energy efficient homes and
schools. Developers are conserving resources by using the recycled
concrete for the mixed-use development and other construction projects
in the Denver metropolitan area.
A study conducted by the Colorado School of Mines found that concrete
aggregate produced from the Stapleton recycling project is of equal
or higher quality than virgin mixes. Plus, the project virtually
eliminates transportation and resulting energy costs.
Also unique to this project, RMC was the first recycling firm to
pioneer and implement a “no-cost” reuse and sustainability
model. The city of Denver and its citizens didn’t pay a penny
to RMC for demolition. The firm sells the
recycled aggregate to developers and contractors.
Energy Efficient ar Any Height
In 2003, the nation’s first green residential high-rise building,
The Solaire, opened with a great deal of publicity and attention
in lower Manhattan’s Battery Park City. Since the landmark
opening, neighboring sustainable luxury structures Tribeca Green
and The Verdesian have opened and Millennium Tower is currently
under construction.
All four structures feature a reinforced concrete structural system,
chosen in large part because its thermal mass helps to moderate
daily temperature swings, reducing energy and costs needed for heating
and cooling.
With this strategically green design, the energy efficiency and
savings can be impressive. “The thermal mass properties of
a concrete wall are superior to other building materials—no
matter the project—building, home, school or hospital,”
says Ed Alsamsam, PhD, SE, PE, and general manager of PCA’s
Building Group.
“A concrete building will cut down on lifecycle cost, offering
more savings for a building owner in terms of energy efficiency
as well as the pocketbook,” Alsamsam said.
Lifecycle Analysis: Concrete in LEED,
Green Globes
David Shepherd of the Portland Cement Association points out
that both the U.S. Green Building Council and the Green Building
Initiative are examining how to incorporate lifecycle analysis
(LCA) into their standards (LEED and Green Globes, respectively).
With a good tool to measure LCA, Shepherd suspects that concrete
will shine. He explains that building a structure and harvesting
the materials accounts for about 2 percent of the energy; the
other 98 percent is used over the lifetime of the building.
|
Ryan M. Puckett has worked in communications during the past
10 years in several capacities, including freelance writer, media
liaison and copywriter. His diverse industry experience ranges from
sustainable construction to organic agriculture, commercial airplanes
and local government.
|  |
|