I-91 Brattleboro Bridge.
Nine outstanding construction projects that used slag cement received 2017 Project of the Year Awards from the Slag Cement Association (SCA) during the American Concrete Institute’s 2018 Spring Convention in Salt Lake City. Each project was selected by the SCA’s Technical Marketing Committee for of its exemplary and innovative uses of slag cement in concrete mix design. Awards were presented for Architectural, Durability, Green Design, High Performance, Innovative Application, and Sustainability.
The following projects were honored:
- Architectural: Barrier One Headquarters – Winter Garden, Fla.; Lehigh Hanson; The building uses 50 percent slag cement in all concrete applications, including foundation, slab-on-grade, paving, sidewalks, casting beds, and tilt-up panels. The concrete over-achieved required strength designations, and the slag cement helped contribute to the superior performance of the tilt-up concrete where early lifting strength was required.
- Durability: I-91 Brattleboro Bridge – Brattleboro, Vt.; LafargeHolcim; Vermont’s first cast-in-place segmental concrete bridge carries Interstate 91 over Vermont Rt. 30 and the West River. Slag cement was used in mass concrete pours and in ternary mixtures to increase bridge strength, reduce permeability, and improve the workability of the concrete.
- Sustainability: Ecole Kenwood French Immersion Elementary School – Columbus, Ohio; Votorantim St. Marys Cement; More than 20 percent slag cement was used as a portland cement replacement to enhance color and reduce overall concrete costs. Slag cement also helped create a more sustainable building by using recycled, local materials and contributes to the buildings overall durability.
- Green Design: NVIDIA Building – Santa Clara, Calif.; Lehigh Hanson; The building, which features a unique triangular design, was created with a focus on seismic activity concerns within the Northern California region. Approximately 65 percent of the concrete consists of 20-30 percent slag as a cement replacement. The use of slag cement also helped reduce the building’s environmental impact, resulting in an approximate savings of 6.7 million pounds of carbon emissions.
- Architectural: Panorama Building – Miami; Lehigh Hanson; The 83-story, mixed-use building uses slag cement in more than 13,000 cubic yards of mat foundation concrete — all vertical elements — and 50 percent of the elevated decks. The slag cement used in mass concrete allowed for higher strength gains and reduced peak heat of hydration.
- High Performance: Tampa Airport Taxiway “J” Bridge Reconstruction – Tampa; Argos USA; The airport recently finished the reconstruction of a 300-foot long by 200-foot wide taxiway bridge built to support the weight of Boeing 777 and Boeing 747 aircraft. A mix design was used with 30 percent slag cement replacement of cementitious material.
- High Performance: Sellwood Bridge – Portland, Ore.; Ash Grove Cement Co.; Slag cement was used at 50 percent replacement of portland cement in mass concrete to lower heat of hydration and had an average strength of over 6,700 psi in 56 days.
- Innovative Application: St. Croix Crossing – Oak Park Heights, Minn.; Skyway Cement Co.; The project team felt slag cement was a must for its beneficial effects on compressive strength, freeze/thaw durability, surface scaling, and rapid chloride permeability. The project included more than 200 mass concrete placements, most including 65-70 percent slag cement.
- Green Design: Zurich North America Headquarters – Schaumburg, Ill.; LafargeHolcim; The almost 800,000-square-foot complex uses used mix designs with slag cement replacement percentages from 18.5 percent to 24.4 percent. Overall, slag compromised approximately 23 percent of the cementitious content in the almost 33,000 yards of concrete.
“The SCA’s awards program does a great job of showcasing how versatile slag cement can be, and how it can help create stronger, more durable, and sustainable concrete structures,” said Ed Griffith, SCA president, in a press release. “These case studies are a great resource for the industry.”
The entire list of winners is available on the SCA website.