Cement and concrete interests have embraced incentives in the U.S. Green Building Council’s LEED v4 rating system and related standards through which project owners and designers view or stand to view cast-in-place, precast and masonry specifications.
The LEED v4 Materials & Resources section stresses life cycle assessments. They are prepared partly from environmental product declarations (EPD), which in turn hinge on data collection instructions and calculations found within product category rules (PCR). Standardized processes governing EPD and PCR development boost project principals’ confidence in specifications drawn to a green building goal. Since USGBC unveiled LEED v4 late last year, the concrete PCR and EPD library has expanded through producer commitment plus oversight of ASTM International or National Ready Mixed Concrete Association, each certified auditors or EPD program operators.
Prior to the formal LEED v4 rollout, the University of Washington College of the Built Environment-hosted Carbon Leadership Forum penned a PCR for concrete; it informed early EPD from California’s Central Concrete Supply, San Jose, and Angelus Block Co., Sun Valley. The latter issued its EPD subject to revision upon the release of “Manufactured Concrete and Concrete Masonry Products” PCR, a draft of which the National Concrete Masonry Association announced in mid-2014. ASTM oversaw that PCR along with the North American Precast Concrete Product Category Rule, developed by a group including the American Concrete Pipe Association, National Precast Concrete Association and Precast/Prestressed Concrete Institute. As the two PCR for manufactured concrete have taken shape, NRMCA has certified plant-specific EPD for members Argos USA and Cemex USA.
More recently, Portland Cement Association, assisted by 10 member companies, announced “Product Category Rules for Preparing an Environmental Product Declaration for Portland, Blended Hydraulic, Masonry, Mortar and Plastic (Stucco) Cements.” The 19-page PDF was released through ASTM and will influence many future concrete EPD.
Recognizing the value of individual and industry-wide EPD, NRMCA has taken documentation to the next level, positioning members to strengthen customers’ green building rating prospects. At the 2014 Greenbuild last month in New Orleans, it announced Industry-Wide (IW) Environmental Product Declaration and Benchmark (Industry Average) Report, disclosing the environmental impacts of concrete production in a wide range of conditions.
The IW EPD lists impacts for concrete ranging from 2,500 psi through 8,000 psi compressive strength, encompassing most material used in residential, commercial and public construction. Mix designs are covered for each strength class, from 100 percent portland cement mixes to ones where fly ash or slag cement represent 50 percent or more of total binder. The Benchmark Report presents the impacts for average concrete mixtures at the national level and in eight different regions. It 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. It calls for a project team to use products totaling at least 50 percent by cost of all materials on the building that demonstrate three impacts below industry average.
The IW EPD elicited a nod from a source neutral by necessity. “USGBC supports the leadership roll the National Ready Mixed Concrete Association and its members have taken to support transparency in the building market,” said Vice President of LEED Technical Development. “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.”
Through investments in EPD and PCR, NRMCA and peer groups are helping keep ready mixed and manufactured concrete producers ahead of a LEED v4-propelled market curve.