Photo Courtesy Suffolk Construction

On April 26, general contractor Suffolk Construction managed the largest continuous concrete mat placement in the city of Boston's history at the downtown Millennium Tower development.

Hudson, Mass.-based subcontractor S&F Concrete marshalled 600 concrete trucks to cast 6,000 cu yd of concrete for the foundation of the $700-million building. The continuous cast lasted 36 hours, starting at 4:00 a.m. The foundation's 8-ksi-concrete mat averages 6½ ft in depth.

It cost $6 million to put in place, including both the concrete and reinforcing bar. The mat will support a 625-ft-tall building with 1.4 million sq ft of space.