Central Concrete Supply’s Visual Album Highlights Solutions Deployed for Bay Bridge Construction

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.

Thirteen-Year Retrospective: Highlights

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.

Rigorous Requirements

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.

Designing for the Famous Bay Bridge S-Curve 2005-2008

A key challenge presented to Central Concrete was how to design a concrete mix for the famous Bay Bridge S-curve—a temporary structure, connecting the older eastern span of the Bay Bridge to Yerba Buena Island that acted as a detour while teams built a new bridge structure. Working with general contractor C.C. Myers, Inc. and subcontractor Conco, Central Concrete designed a concrete mix that could: (1) be pumped across an extraordinary distance of 2000 feet including 300 feet vertically; (2) achieve very high strength properties; and (3) be easily supported by the steel superstructure.

Central Concrete worked with BASF, the leader in developing chemical admixtures for concrete, to design solutions to meet these aggressive requirements. Through leading-edge chemistry and material science expertise, Central and BASF engineered a highly flowable, lightweight concrete that achieved the required compressive strength and other durability requirements.

The concrete mixes for this application, along with the other mixes for the Bay Bridge, underwent extensive testing in Central Concrete's Lab and then verified by San Jose State University's Civil Engineering department.

"Central Concrete's performance on this complex project was exceptional," said Bob Coupe, project manager for C. C. Myers, Inc. "Their technical and operational capabilities coupled with their dedication to project safety contributed greatly to the success of the project. They were an integral part of the team."

Final Deck Section Placed, March 2013

The final deck of the San Francisco-Oakland Bay Bridge's East span was placed on March 9, 2013, creating the finishing section of the Bay Bridge's cast-in-place concrete roadway decks.

Beginning at 7:00 a.m. on March 9th, 136 Central Concrete trucks began delivering 1,266 cubic yards for the Oakland Touchdown eastbound roadway. The 1,079-foot section—an area equal to about two city blocks—was placed and finished within nine hours. The completion of the East Span ensured that the westbound and eastbound lanes of the new bridge would open to traffic simultaneously, a key milestone set for the 2013 Labor Day Opening. To learn more about the March 9, 2013 placement, go to: ABC KGO Video

Acknowledgements/Team Members

Central Concrete would like to acknowledge these outstanding partners that made this massive undertaking possible:

About Central Concrete

Central Concrete Supply Co., Inc., a business unit of U.S. Concrete, Inc. (Nasdaq:USCR), has been serving the San Francisco Bay Area for more than 60 years. The company is recognized for engineering higher-performing concrete than traditional concrete, while significantly lowering carbon footprints with its low-C02 mixes.

Unlike traditional concrete, Central's standard mixes deliver 50% or greater cement replacement materials, thereby significantly reducing the carbon footprint of the project under construction. Central Concrete is recognized for supplying its low-CO2 mixes to numerous San Francisco Bay Area signature projects, including the Cathedral of Christ the Light Church, Oakland; California Academy of Sciences, San Francisco — the world's greenest museum; NASA Ames Sustainability Base, Mountain View — the greenest federal building in the U.S.; David and Lucile Packard Foundation, Los Altos — largest net-zero private office building in Calif.; the San Francisco Public Utilities Commission (SFPUC) headquarters — San Francisco's greenest office building; and the new Santa Clara 49er Stadium.

With 12 locations in the San Francisco Bay Area, Central Concrete offers multiple points of service to meet the diverse operational needs of its customers. For more information, visit www.centralconcrete.com.

About U.S. Concrete

U.S. Concrete services the construction industry in several major markets in the United States through its two business segments: ready-mixed concrete and aggregate products. The Company has 105 fixed and 10 portable ready-mixed concrete plants and seven producing aggregates facilities. During 2012, U.S. Concrete produced approximately 4.8 million cubic yards of ready-mixed concrete and approximately 3.3 million tons of aggregates. For more information on U.S. Concrete, visit www.us-concrete.com.

Source: http://centralconcrete.com

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