Nominee
Metropolitan Park Phase 7 and 8
Category
Innovative Project
Description
Metro Park Phase 7 and 8 is one of the two buildings that are the centerpiece of Amazon’s HQ2 project in Arlington, Virginia. Sitting atop a foundation consisting of more than 26,000 CY of mass concrete, the building consists of 4 levels of parking below grade, above which an office building spans up 24 levels. The mixes utilized during construction of the building were extremely innovative in moving concrete construction towards a more green industry and are expected to be forerunners for the construction industry as a whole. Specially designed to combine recycled products with traditional concrete materials, they allowed Miller & Long to exceed the projects goals of providing the most eco-friendly construction materials.
Slag cement was used as a supplementary material to lower the embodied carbon values for all concrete in Metro Park 7 and 8.
From the mass concrete of the mat foundations through the final slab, every mix utilized by Miller & Long utilized high quantities of slag.
Slag cement enabled Miller & Long to minimize the Global Warming Potential (GWP) of the concrete mixes as required by the project specifications. Strength of concrete was never affected by the inclusion of as much as 75% of the cementitious material of mixes being slag.
Miller & Long is an NRMCA member company.
Evidence
This project most recently won a Slag Cement Association award for high-performing project of the year for it's high-content slag use in reducing GWP values to levels not before seen in commercial structural concrete construction. Please see the attached EPDs for the most utilized mix designs on the Mets 7&8. Note that the lowest percentage improvement for the project was 30% against the regional average at that time. For the mass concrete mix, the improvement was nearly 60% against the regional baseline, which was a 6,000 psi mix (our mass concrete was 7,000 psi).
Additionally, we had not one low-break over the course of the project with these high-performance mix designs!
These concrete mix designs were produced at a near-site batch plant run by Miller & Long.
Miller & Long is an NRMCA member company.
Images (click to expand)
