Concrete Choices for the Environment

Doug O'Neill

Concrete is one of the oldest and most versatile building materials on the planet. For thousands of years concrete has been the miracle material that can be molded into any shape or size imaginable; can be colored, stamped or stenciled to be made to look like brick or stone or even wood; and then, as if by magic, this "wonder" product gets hard like stone and creates strong, durable structures and pavements that last.

From the homes and offices we live and work in, to the roads, bridges and sidewalks we travel on, people have come to count on concrete every day of their lives. That sounds like a pretty amazing product. You would think a material this exciting would be on the minds of most people much of the time, and kids would dream of becoming involved in the wonderful world of concrete.

So what's up with our lackluster reputation? Why the general indifference to this "totally awesome" material? Is it because concrete has been around so long and is always there that people take it for granted? Or, because most people don't really know much about concrete? Whatever the reason for this apathy toward this magnificent building material, take heart, concrete fans, because "times, they are a changin'!"

Because of today's environmentally conscious marketplace, concrete is now beginning to stand out as a solution to sustainable construction requirements. You can't pick up a newspaper or construction-related publication today without seeing some kind of article about "green building" or "sustainable construction."

What surprises many is that concrete offers tremendous advantages from an environmental aspect. Suddenly, the construction industry is looking at this less-than-glamorous product, used in virtually every phase of construction, with a new appreciation and a willingness to recognize unique applications such as pervious pavements and insulated stay-in-place form construction.

One of the major factors driving the green building movement is the realization of how much waste goes into the construction and operation of the buildings we live and work in. Think for a moment about how much time we spend indoors. Our buildings have a huge impact on our environment, even when we are not in them. But what if we could design, construct and operate our buildings using sustainable thinking, meeting the needs of today without jeopardizing future generations from meeting their own needs?

The U.S. Green Building Council developed a program called LEED, which stands for Leadership in Energy and Environmental Design and has become the prominent green building rating system. There are four different thresholds for LEED certification recognizing varying levels of achievement: Certified, Silver, Gold and Platinum. LEED-NC (New Construction) promotes improved practices in site selection and development, water and energy use, environmentally preferred construction products, waste stream management and indoor environmental quality. Within each category, project teams choose which credits to pursue based on their environmental and performance goals.

The use of concrete can contribute to earning more points toward project certification than any other building material. For the purpose of this article let's take a look at a few credits where the use of concrete makes a difference toward earning points.

Sustainable sites
Under this category, the use of pervious concrete pavement qualifies for credits SS 6.1 Stormwater Design-Quantity Control and SS 6.2 Stormwater Design-Quality Control. Keeping our aquifers, lakes, rivers and oceans free from pollution is a massive job. Conventional impervious pavements, particularly parking lots, collect pollutants that can be washed into streams, lakes and oceans. Pervious concrete pavements can reduce or eliminate stormwater runoff and permit the treatment of pollutants on site. By capturing rainfall and allowing it to percolate into the ground, soil chemistry and biology are allowed to treat the polluted water naturally.