Castroville, Calif.-based Ausonio, Inc. specified ground granulated blast furnace (GGBF) slag cement for concrete used in 26,000 sq. ft. of slabs at the
Castroville, Calif.-based Ausonio, Inc. specified ground granulated blast furnace (GGBF) slag cement for concrete used in 26,000 sq. ft. of slabs at the Chartwell School’s new campus in Seaside, Calif. The mix design is aimed at helping the school achieve Platinum LEED [Leadership in Energy and Environmental Design] certification from the U.S. Green Building Council (USGBC). To support the school’s green building goals, Don Chapin Ready Mix Division in Salinas, Calif., designed the concrete mix incorporating slag to achieve a high-quality product that is stronger, sustainable and lighter in color. Lehigh Southwest Cement of Concord, Calif., provided the slag cement.
A 99 percent byproduct of iron ore production, processed slag provides an equivalent 70 percent reduction in carbon dioxide emissions when used in lieu of 100 percent portland cement in ready mixed formulations, Ausonio notes. Recognizing its environmental benefits as a concrete mix component, the Environmental Protection Agency classifies slag cement as a recovered product under the Resource Conservation Recovery Act, and issued a procurement guideline requiring its specification on most federally funded projects. Additionally, Ausonio representatives contend, slag cement reduces the environmental impact of concrete by (a) minimizing energy consumption, since a ton of slag cement requires 90 percent less energy to produce than a ton of portland cement; (b) reducing the amount of virgin material extracted to make concrete; and, (c) decreasing the urban heat island effect by making concrete lighter in color and more reflective, thereby cooling structures and pavements with exposed concrete surfaces.
Concurrent with the Chartwell School construction is USGBC’s development of a LEED for Schools rating guideline. Targeting a market-specific application, the organization notes, the document recognizes the unique nature of K-12 school design and construction. The draft rating system is based on LEED for New Construction and addresses issues such as classroom acoustics, master planning and mold prevention. When complete, LEED for Schools will be supported by a full suite of tools tailored to education facility design: a reference guide, workshop, and LEED Online with credit templates.
Comments on the guideline’s first draft were solicited Aug. 10 through Sept. 10 by the Council from anyone registering a site user profile on www.usgbc.org. Responses (without commenter names or organizations) will be posted on the USGBC Web site, along with a draft showing all changes to LEED for Schools. The group will then open a second public comment period on those changes. The resulting draft will be sent to the USGBC membership for balloting. Official public release of the application guide is expected by winter 2006.
Architects behind Illinois’ first green high school call on Northfield block
Bolingbrook High School (BHS), of Valley View School District 365U in southwest suburban Chicago, recently became the first public school in the state Û and third high school nationwide Û to become LEED certified. The 560,000-sq.-ft. facility was delivered in 30 months by Wight & Co., Darien, Ill., using a design/build method. BHS opened in 2004 on a 70-acre, tiered site that Wight officials note promotes an intimacy typical of smaller facilities without sacrificing the cost benefits of a larger structure. Mundelein, Ill.-based Northfield Block provided concrete masonry units for wall construction that contributed to LEED certification goals by using local resources and providing higher insulation values.