The National Ready Mixed Concrete Association (NRMCA) announced at Greenbuild 2014 held this week in New Orleans that it has published a set of industry average environmental impacts for concrete to help its members address the movement toward product transparency in LEED v4.
These NRMCA documents, known as an Industry-Wide (IW) Environmental Product Declaration (EPD) and Benchmark (Industry Average) Report, disclose the environmental impacts of concrete manufacturing for a wide range of concrete products. EPDs are third-party verified reports published by product manufacturers that provide quality assured and comparable information regarding environmental performance of their product.
US Green Building Council’s (USGBC) LEED v4 Green Building Rating System has a credit that encourages a project team to use 20 different products on a project that have EPDs. For concrete, a product is defined by each unique mix supplied on the project. Since concrete can be used for applications ranging from foundations to floors, columns to curbs, beams to parking lots, it usually provides several products on a project.
According to LEED v4, for a company to use an IW EPD, it must have provided data to the project and be listed in the EPD. Although the IW EPD is worth half the value of a product specific EPD, nearly 70 NRMCA member companies, representing nearly 2,300 concrete plants, are represented by the IW EPD.
Environmental impacts disclosed in the EPD, including Global Warming Potential, Ozone Depletion Potential, Acidification Potential, Eutrophication Potential and Photochemical Ozone Creation/Smog Potential along with other impacts such as depletion of non-renewable energy resources, waterconsumption and waste, as is required by the international standards and LEED v4.
The IW EPD lists impacts for concrete ranging compressive strength from 2,500 psi through 8,000 psi covering most concrete used in residential, commercial and public construction. A wide range of products (mix designs) are covered for each strength class, from 100 percent Portland cement mixes to mixes with over 50% replacement with fly ash and slag cement.
The Benchmark (Industry Average) Report presents the impacts for average concrete mixtures at the national level and in eight different regions of the country. This allows companies to compare their product-specific environmental impacts to industry averages and potentially participate in the second option of the LEED v4 EPD credit. This option requires a project team to use products totaling at least 50 percent by cost of all materials on the project that demonstrate three impacts below industry average.
Brendan Owens, USGBC vice president of LEED technical development, said: “USGBC supports the leadership roll the National Ready Mixed Concrete Association and its members have taken to support transparency in the building market. The information in this Environmental Product Declaration will allow LEED project teams to make more informed decisions on how the concrete materials they specify affect the embodied environmental impact of buildings.”
“By publishing the IW EPD and industry baselines for concrete we are helping concrete producers accelerate their progress toward reducing their environmental impacts and supporting the drive toward product optimization through disclosure,” NRMCA President Robert Garbini says.
The IW EPD and baselines were developed by Athena Sustainable Materials Institute. The EPD was third-party verified by NSF International. The Product Category Rule (PCR), the standard by which EPDs are developed, was published by the Carbon Leadership Forum. In addition to the IW EPD and Benchmark Report, several NRMCA members have published product specific EPDs covering more than 2,000 products, the most of any other industry.