The final deck section of the San Francisco-Oakland Bay Bridge’s new east span was poured on Saturday, marking another milestone in the completion of the new east span. While work remains on the new bridge to prepare it for its Labor Day weekend opening, including installing expansion joints in the road decks and paving, the concrete pour at the eastern end of the eastbound deck created the final section of the bridge’s decks.
Starting at 7 a.m., approximately 136 trucks began delivering 1,220 cu yd of concrete to fill a 1,079-ft-long section of the Oakland touchdown’s eastbound roadway; each truck can carry 9 cu yd. The prime contractor on this Oakland touchdown contract is Flatiron West Inc. The Oakland touchdown is the 4,229-ft-long easternmost section of the new span.
As the concrete is poured by a pump truck, a machine called a bidwell will flatten the concrete and provide a smooth finish and then place longitudinal grooves into the concrete’s surface to help reduce noise. After the concrete is poured, it will set within two to four hours but will need to be water cured for seven days; during this process water will be sprayed onto the concrete, and blankets will be used to keep the water from evaporating. After the concrete has cured, Flatiron will strengthen the deck section by running steel tendons through it, a process known as post-tensioning.
This milestone was more than two years in the making. The original bridge’s westbound lanes were in the way of the new bridge’s eastbound lanes near the toll plaza. Initially, final construction of the eastbound lanes would not have started until westbound traffic started using the new span, while eastbound traffic stayed on the original span for four to six months. By moving the eastbound lanes slightly south in May 2011 and realigning westbound lanes during Presidents Day weekend in 2012, crews ensured that the west- and eastbound lanes of the new bridge could open to traffic simultaneously.
Flatiron is based in Firestone, Colo.; the company’s Bay-Area office is in Benicia. A previous Oakland touchdown contract oversaw construction of the westbound roadway and part of the eastbound roadway. The concrete was supplied by Central Concrete of San Jose, Calif., from its Oakland facility.
The 1.2-mile-long Skyway was completed in April 2008, the last deck section of the self-anchored suspension span was placed in October 2011, and the Yerba Buena Island transition structure’s road decks were completed by the end of 2012.
The Toll Bridge Program Oversight Committee (TBPOC) consists of the California Department of Transportation (Caltrans), the Bay Area Toll Authority (BATA) and the California Transportation Commission (CTC).