Celebrating the opening of the San Francisco-Oakland Bay Bridge, Central Concrete Supply Co., Inc., a business unit of U.S. Concrete, Inc., and the leader in delivering low-CO2 concrete to the San Francisco Bay Area, has posted a photo gallery showcasing the innovative concrete solutions deployed for the Bay Bridge construction project. This Visual Album, "The Bay Bridge, A Thirteen-Year Retrospective," provides visitors with a unique view of the enormity of the Bay Bridge project.
By the Numbers
Central Concrete started work on the San Francisco-Oakland Bay Bridge in 2001. Twelve years later, Central Concrete has supplied over a quarter of a million cubic yards of concrete—equivalent to covering a football field with concrete, 153 feet thick. At peak times, Central Concrete utilized four plants, 60 trucks at a time (using 136 trucks for the East Span Deck pour alone), and multiple 12- to 16-hour pours, including several overnight placements.
The Bay Bridge project entailed a number of rigorous requirements, such as concrete durability, CO2 reduction, rapid setting and pumpability. To meet these requirements, Central Concrete engineered more than 40 specialty mixes, leading to many new performance milestones. Not only were the mixes optimized to deliver the aggressive performance specified for this large-scale, technically challenging project, but Central Concrete's use of 25 percent to 50 percent cement replacement materials significantly reduced the Bay Bridge's carbon footprint. The low-C02 mix designs resulted in at least 60 million pounds of CO2 reduction, as compared to traditional Portland cement concrete.
"Central Concrete, at every turn, was ready to take on the uncompromising demands presented by the Bay Bridge Project," said Greg Allen, project manager for MCM Construction, one of the lead contractors on the bridge project. "We selected Central Concrete for their deep technical expertise, outstanding problem-solving skills, and ability to deliver the highly engineered mixes required for this job. At the same time, they offered the broad and deep resources necessary for this enormous project, while running their business with the personal care seldom found in large companies."
"Central Concrete is uniquely capable to develop and produce high performance and highly sustainable concrete in the Bay Area," said Tarek Khan, market development manager, for BASF Construction Chemicals, Admixtures Systems. "Central Concrete's technical team, research laboratory, production capabilities, and their management's focus on innovative, sustainable concrete have put them in a class by themselves to meet technical and operational challenges like the Bay Bridge project."
Three-Day Demolition and Roll-in, Labor Day Weekend 2007
Labor Day weekend 2007, crew members began a campaign dubbed by C.C. Myers, Inc., the lead contractor for this project, as "We rocked, it rolled."
Following closure of the bridge at 8:49 on Friday night, team members removed a football field-size section—348 feet long by 75 feet wide—of the San Francisco Bay Bridge deck on Yerba Buena Island, rolling in a pre-constructed replacement span and placing the replacement concrete.
Within 49 hours, each of the 48 deck and beam sections, weighing an average of 85 tons, was hoisted and removed. Crews then began the roll-in of the 6,700 ton replacement structure built by C.C. Myers, Inc. The new structure was moved into place in just under two hours; the teams quickly installed the joint seals in preparation for the last steps: the concrete placement and finishing.
To meet the aggressive schedule, Central Concrete engineered a concrete mix with extremely fast strength gain. Central's ability to deliver a concrete mix that was ready for vehicle traffic within four hours contributed to the team's ability to have the bridge striped and open to traffic at 6:00 p.m. Monday—11 hours ahead of the opening deadline of Tuesday at 5:00 a.m.