Amazon’s New Arlington Headquarters is on the Rise

December 11, 2020

Amazon’s New Arlington Headquarters is on the Rise

The first phase of Amazon’s second headquarters is taking shape in the heart of National Landing, a newly dubbed region that spans Arlington County and the City of Alexandria. Following nine months of early building activities, including a substantial mass excavation effort, which involved the removal of 440,000 cubic yards of soil, construction crews are taking another important step in the project’s delivery: going vertical.

Clark marked the start of concrete operations on the project, otherwise known as Metropolitan Park, Phases 6, 7, & 8, in early October. The milestone kicks off the placement of nearly 200,000 cubic yards of concrete, which will be used to form the superstructure for the project’s two 22-story buildings. Four tower cranes have taken rise over the last several weeks to support the operation with a fifth being erected later this month. To sustain the volume of concrete needed for the project over the next 17 months, the team has also assembled a concrete batch plant at a vacant site just blocks from the job. Additional concrete is also being sourced from an Arlington-based plant a few miles away. Clark Concrete and Miller & Long Concrete are managing concrete operations on buildings 6 and 7 & 8, respectively.

Furthering its longstanding commitment to sustainability, Amazon set the ambitious goal of earning LEED® Platinum certification for its new Arlington campus. As one of many strategies to achieve this outcome, the construction team is utilizing both CarbonCure concrete technology and Supplementary Cementitious Materials (SCMs) to help reduce the project’s carbon footprint. The CarbonCure system injects a precise dosage of carbon dioxide (CO₂) into the concrete, where the CO₂ solidifies and becomes chemically converted into a mineral. The CarbonCure process not only reduces the environmental impact of construction, it also improves the concrete’s compressive strength, making the structure more resilient. Similarly, the team is leveraging SCMs, such as slag cement, to reduce energy, greenhouse gas emissions, and the use of raw materials. An industrial byproduct of an iron blast furnace that can be chilled and ground to a desired fineness, slag also yields improved performance and increased durability.

The project team will measure the reduction in the project’s carbon footprint through the Global Warming Potential (GWP) value, a unit of measurement that assesses the quantity of CO₂ emissions created by the production of concrete using standardized life cycle assessment methodologies.

Encompassing 2 million square feet of sustainable office space, and another 1 million square feet of below-grade parking and support areas, Metropolitan Park is the largest active construction site in the Washington, DC metropolitan market. To maintain the project’s aggressive schedule, the Metropolitan Park team is placing nearly 3,000 cubic yards of concrete per week on average. With approximately 300 craftworkers currently onsite, that number will continue to grow to as many as 1,200 craftworkers before the project tops out in Spring 2022.