Urban metamorphosis is underway in Washington, D.C., and the new NoMa district nestled between Union Station and the U.S. Capitol is a hotbed of construction activity, including the new 560,000-square-foot Union Place mixed-use development project. This 14-story building will include 525 residential apartments, 13,000 square feet of retail space, below-grade parking and a rooftop lounge with Capitol views. It will also feature 1,000 high-quality precast/prestressed concrete foundation piles produced by Atlantic Metrocast Inc. using an advanced self-consolidating concrete.
Fabrication in Maryland
The 20-foot-long, 14-inch-square foundation piles for the Union Place development were produced at Atlantic Metrocast’s PCI-certified facility in La Plata, Md., which is strategically located adjacent to an Aggregate Industries ready-mix concrete plant. The process for producing the precast, prestressed concrete piles started with a thorough cleaning of the formwork, spraying the casting bed with a very light mist of an oil-based release agent to prevent the bonding of concrete, setting the bulkheads to the specified lengths, and stringing the half-inch-diameter steel prestressing strands.
Production Challenges
Precast concrete producers are continually searching for creative new approaches to work faster, reduce operating expenses and eliminate the production of off-spec products to achieve a competitive advantage. For Atlantic Metrocast, this new approach to improving precast production times and finished product quality was found in making a switch from using conventional concrete to an advanced self-consolidating concrete (SCC) technology.
Called Agileflow® (formerly known as Agilia), this custom-designed concrete product places more quickly, flows easily through congested reinforcement and provides superior non-segregation properties for greater structural integrity. Other advantages of using the LafargeHolcim SCC technology include increased strength, reduced production times and labor costs, higher-quality finished surfaces, and improved jobsite safety due to the elimination of vibration requirements...
This article was originally published in The Concrete Producer's May 2017 Issue.
