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Concrete & LEED
Understanding 'Green' Concrete

Below is an example of a Terrazzo concrete top.

As both a pioneer in the fabrication of concrete countertops and a leading manufacturer of artisan concrete products, we are often asked the question that seems to be on everyone's mind: Is a concrete countertop considered green, and how can that impact LEED certification?

First, we need a basic understanding of what LEED means. The Leadership in Energy and Environmental Design (LEED) Green Building Rating System, developed by the U.S. Green Building Council (USGBC), provides a suite of standards for environmentally sustainable construction.

How Does LEED Work?

LEED-certified buildings use key resources more efficiently when compared to conventional buildings, which are simply built to code. LEED-certified buildings have healthier work and living environments, which contributes to higher productivity and improved employee health and comfort. The USGBC has also compiled a long list of benefits for implementing a LEED strategy which ranges from improving air and water quality to reducing solid waste -- benefiting owners, occupiers and society as a whole.

Without going into great detail (you can visit www.usgbc.org/leed if you would like the details), LEED certification involves a point system that provides levels that range from Certified (40 to 49 points) to Platinum (80 points and above). A key piece of this scoring system involves materials, and that is where concrete can play a major role.

Is Concrete Green?

Before discussing how concrete countertops may provide valuable LEED points, we must have an honest discussion: How green is concrete? There are a lot of claims concerning whether concrete is or isn't green. The truth, like in so many other things, is mixed. In order for you make a decision about the "green-ness" of concrete, here are some things to think about.

Is concrete free of chemicals? Concrete can be made from all natural material, or have a lot of chemical additives. So it is important to understand what is in the mix being used on a project. Concrete does not off-gas chemical air pollutants.

Where does concrete come from? The main components of concrete are local and abundant. The ingredients of concrete are abundant in supply and easily accessible. Quarries, the primary source of raw materials, can be reclaimed for recreational, residential or commercial use, as well as be restored to their natural state.

What about the cement? The process of creating Portland Cement, the main active ingredient of all concrete, is an energy intensive process, requiring a lot of water and high temperatures generally in a coal- or gas-fired furnace. Anyone who calls their concrete "green" without addressing the impact of cement is avoiding this key issue. Fortunately, there are several innovative companies looking at revolutionizing the creation of Portland Cement that will have a profound environmental impact on producing the cement used in concrete.

What types of aggregate are used? The fabricator may use a variety of "post consumer" materials, such as recycled glass. We have extended the amount of cement used relative to the square feet covered by adding recycled material such as rock, glass, broken up oyster and abalone shells, CD pieces, old coins, metal shavings and jewelry. Only your imagination limits the possibilities. Again, a handful of innovative companies are focused on delivering concrete that uses up to 90 percent recycled aggregate in its formulation, requiring no mining of new aggregates.

Does fly ash really contribute to making concrete more green? Fly ash is a byproduct of coal-fired electrical plants that can be added to concrete in place of sand. It is reactive enough to substitute for some cement (varying from mix to mix), which is its main green contribution. Of course, it needs to be collected, packaged and transported to the ready mix or batch plant, which could negate some of the green impact compared with locally produced cement.

What Does This Mean To Fabricators?

Now that you have some knowledge about LEED and concrete, one can fabricate countertops using concrete in a way that earns important LEED points that can be applied to certification. For example, a LEED point can be earned by using local materials -- concrete can certainly meet this requirement. Up to two LEED points can be earned through the use of recycled content, also achievable through the use of recycled aggregates and fly ash. So in summary, current products and practices can be incorporated to positively impact LEED certification. There is also a great deal of excitement about new products soon to hit the market that may revolutionize the way concrete is produced for a greener future.

About the author: Keith Couch is vice president of sales for Buddy Rhodes Concrete Products. He can be reached at 415-431-8070.