Lafarge NewCem slag cement and Agilia self-consolidating concrete are playing a major role in the construction of the new Midtown Tunnel under the Elizabeth River in Hampton Roads, Va. When the tunnel opens in 2016, it will double traffic capacity between the cities of Norfolk and Portsmouth, helping to alleviate traffic congestion and the resulting lost millions of dollars in time, productivity and economic development.
A Lafarge team is working at a large dry dock in Sparrows Point, Md., to build the 4,800-ft., two-lane tunnel’s 11 reinforced concrete elements. Each element comprises five sections requiring separate concrete pours – 55 in all. Two portable on-site plants are producing 72,000 cu. yd. of Agilia concrete, which contains NewCem slag cement.
Agilia self-consolidating concrete significantly reduces construction time and cost by eliminating the need for vibration due to its fluid and stable properties. Engineered for high strength and long-term durability, NewCem slag cement helps achieve greater strength potential and helps control shrinkage, creep and cracking in mass concrete structures.
The first six concrete tunnel elements arrived at the project site this summer, after being towed one at a time by a tug fleet 220 miles down the Chesapeake Bay from the Sparrows Point docks. The remaining five tunnel elements are scheduled to arrive at the Portsmouth Marine Terminal in spring 2015. On Oct. 10, the Elizabeth River Tunnels Project Team put in place the first section of the new Midtown Tunnel, which will eventually serve as the westbound exit to Portsmouth.
Since the original tunnel opened in 1962, traffic along the route has increased by 600 percent. Once the new tunnel is complete, the existing one will be rehabilitated, and together they will expand capacity to two lanes of traffic in each direction.