The Greening of—Concrete?

Source:www.stonediamondtool.com Date:2020/7/3 Read:294

New CSU, Chico Program Smoothes the Way

January 2007

Concrete is fast gaining recognition as a worthy element of sustainable construction projects, and California State University, Chico’s new Concrete Industry Management (CIM) program within the College of Engineering, Computer Science, and Construction Management is spreading the word.

According to Kristin Cooper Carter, director of the CIM program at CSU, Chico, the University is laying a solid foundation for “the greening of concrete.”

One of only four CIM academic programs in the nation, CSU, Chico’s project is a joint initiative including three other universities—Arizona State University, Middle Tennessee State University, and the New Jersey Institute of Technology—and national leaders from the concrete industry. The CIM program at CSU, Chico is designed to serve the industry’s management training needs for the western region of the United States.

“Our goal is to create a demonstration green building obtaining as many LEED points as possible through the application of concrete,” Cooper-Carter says. “The idea is that people can come here to see what a polished concrete floor or insulated concrete form wall looks like.   The building will serve as a hands-on education tool for both industry professionals and students.  A building like this does not currently exist anywhere in the nation.  Industry professionals can also come here for certification workshops on a variety of topics, such as how to apply pervious concrete and learning new construction techniques.”

Cooper-Carter, who holds a masters degree in Program Administration and Evaluation from CSU, Chico, is also director of the college’s Office of Environmental Programs and has served as project director for other environmental projects—both on and off campus—for more than 10 years.  Her main program focus is sustainability in the built environment.  In 2004 she was honored as outstanding project director of the year by the CSU, Chico Research Foundation. 

Concrete Goes Green
Concrete offers a multitude of environmentally friendly characteristics, Cooper-Carter says.

First, concrete is recyclable. “Crushed down,” it’s useful as a very durable road or construction base. Building projects gain points during the U.S. Green Building Council’s LEED (Leadership in Energy and Environmental Design) certification, in fact, if they include reused concrete.

Second, the modern concrete-making process can “trap” or otherwise remove unwanted carbon dioxide (CO2) byproducts—including fly ash, the inorganic residue left over from steelmaking and coal combustion—from the environment. Fly ash can substitute for up to 50 percent of the Portland cement in concrete used for patios, sidewalks, and buildings. (Concrete with fly ash also gains LEED points.) Organic CO2 sources such as rice straw or recycled tires can also be incorporated into concrete.

Third, concrete provides excellent thermal mass for passive solar energy construction projects. Poured concrete flooring, which can be stamped, stained or dyed in many colors or color combinations–colors that never fade—can also be textured as safe, non-slip surfaces. Radiant heat, powered by the sun or otherwise, can also be incorporated into concrete floors.

Fourth, the thermal mass of concrete can greatly improve a building’s overall energy conservation profile.

Similar to SIPs or structural insulated panels, insulated concrete form or ICF walls incorporate insulating foam to offer energy efficiency; easier, quicker construction; and freedom from moisture retention. Concrete walls can be designed for a southern exposure, so that the exterior surface collects solar heat and radiates it to the building’s interior. Western walls, by contrast, would feature few windows and offer much thicker insulation.

Concrete roof tiles can be painted to reflect rather than absorb the sun’s rays. To reduce the urban heat-island effect or albedo, very thin concrete-based “white topping” also can be applied over asphalt road and parking lot surfaces.

Fifth, concrete can offer surprising aesthetic appeal while making good use of post-consumer recycled materials. Syndecrete®, for example, is a pre-cast lightweight composite concrete—incorporating metal shavings, ground plastics, recycled glass chips, and scrap wood chips, among other materials—developed by architect David Hertz as an alternative to limited or nonrenewable natural materials including wood, stone, and synthetic petroleum-based materials. Syndecrete® and other composites are used in floor tiles and wall panels, counters and tabletops, furniture, and fixtures.

The Protective Power of Pervious Concrete
Finally, concrete can be used to protect and enhance rather than disturb the natural environment.

Most notable here, says Cooper-Carter, is “pervious concrete,” or concrete that can be permeated by water, which reduces or eliminates the need for storm drains and water retention ponds in housing and other developments. Known and utilized in Europe for 80 years and for 30 years in the United States, pervious concrete is as strong and durable as regular concrete, and will carry the weight of both cars and trucks for 50 years. Water goes through pervious concrete at the rate of 400 inches per hour.

If paved roads, driveways, parking lots, tennis courts, and pool areas were paved with durable pervious rather than impervious materials, she points out, toxic pollution reaching streams, rivers, and oceans—the “big flush” effect following storms—would be almost eliminated. Because pervious concrete hosts a rich microbial soil environment, pollutants including hydrocarbons, nitrates, and phosphates are easily digested. To further improve groundwater quality, crushed, reused concrete can serve as a natural filter.

By retaining storm water runoff, pervious concrete can also help replenish and “recharge” local watershed systems. Rather than preventing the infiltration of water into soil, like most paving surfaces, pervious concrete “captures” rainwater in a network of “voids” that allow it to percolate into the underlying soil.

Concrete has only one major environmental drawback, according to Cooper-Carter—the amount of carbon dioxide (CO2) the initial cement-making process releases into the atmosphere. The industry is now working hard to replace old plants with newer technologies and otherwise support innovative ways to improve the concrete manufacturing process.

Another potential negative is price. But given its durability, and as other construction materials become increasingly scarce and costs rise accordingly, concrete is becoming increasingly competitive.

A pervious concrete demonstration is on permanent display at CSU, Chico—the walkway leading from the intersection of Warner and West First Streets to the H. F. Langdon Engineering Center.

Sponsors for the pervious concrete demonstration and initial installation course included A&A Concrete Supply, Inc., Baldwin Contracting Company, Inc., Bunyan Industries, and the Pacific Southwest Concrete Alliance.

Promoting a Progressive Concrete Industry
Concrete materials and products are the foundation of the $931 billion construction industry in the United States, one of the primary drivers of the nation’s economy. The CIM program at CSU, Chico, unique in California, was created with expertise and strong financial support offered by industry executives who are eager to employ program students as on-site interns and graduates.

Concrete companies and organizations actively support this program through funded research, equipment donations, guest speakers, and sponsored industry forums. To date, the concrete industry has invested nearly $3 million in CSU, Chico’s concrete program.

The multidisciplinary four-year bachelor of science degree in Concrete Industry Management at CSU, Chico, still awaiting official approval by the CSU Chancellor’s Office but otherwise already underway, prepares women and men for a wide variety of progressive professional careers.