The New I-35W Bridge Counted on Concrete

In September 2008, crews placed concrete to close the final gap on the new I-35W Bridge in Minneapolis. The St. Anthony Falls Bridge opened to traffic on September 18, 2008, more than three months ahead of schedule.

High-performance concrete contributed to the cost-effectiveness and accelerated construction of the bridge and its great looks. Segments for the bridge’s superstructure were cast using eight casting beds along the project site. These casting beds were all producing concrete segments simultaneously, even during the winter months. Concrete construction also means lower maintenance and repair costs for decades to come.

With a reported 100-year life span, ten lanes of traffic, and the ability to accommodate future light rail transit, the new bridge is an example of a quality infrastructure project. The project also demonstrated unique ways of involving the public—both during the design and construction phases of the project. As part of the design process, invited public participants chose between pier types, color of the bridge, lighting options, rail designs, and wall styles. During construction, both Minnesota DOT and the contractor informed the public using weekly e-mails including photos and Saturday morning informational status talks on-site that were open to all.

FIGG Engineers, the designers of the bridge, have published a book describing the design and construction of the bridge. All proceeds from the sales of Bridging the Mississippi benefit “Admission Possible, ”a charity which helps promising low-income students in the Minneapolis-St. Paul area achieve their dreams of college. For more information on this book, click here.

Photos courtesy of FIGG and Tim Davis.

Don't Miss the Next Issue of HPC Bridge Views

HPC Bridge Views, the newsletter which keeps you informed of the latest high-performance concrete (HPC) project and research news, is now available only in electronic format. You must sign up for the electronic version of HPC Bridge Views even if you were a past subscriber. Sign up now.

You can also read and download previous issues of the newsletter. These issues contain articles on projects such as the San Francisco-Oakland Bay Bridge, the Woodrow Wilson Memorial Bridge, and the Cooper River Bridge, as well as topics such as reducing bridge deck cracking, thermal issues in HPC, the use of self-consolidating concrete in bridges, and preventing alkali silica reactivity. Visit the website: www.hpcbridgeviews.org.

2008 Professors’ Seminar Bridges the Gap

The 2008 seminar was held August 7-8 in Skokie, Ill. and 19 professors attended. The professors were sponsored by PCA Regional Promotional Groups, Cement Association of Canada regions, and other local cement and concrete industry groups. The seminar was conducted by PCA and co-sponsored by the Precast/Prestressed Concrete Institute and the Post-Tensioning Institute. Each professor received a design notebook as well as electronic copies of presentations and design examples.

The professors’ seminar is offered once a year in an effort to provide training and resources in state-of-the-art procedures for concrete bridge design from the AASHTO LRFD Bridge Design Specifications. The training and resources enable professors to introduce a new bridge design course into their school’s curriculum or to include bridge content into existing reinforced and prestressed design courses. The professors are also better able to help their local Departments of Transportation when bridge design questions arise.

Contact Sue Lane for information on how you can attend next year’s seminar.

Concrete Bridges Rated More Structurally Sound

For all classes of road or highway systems, reinforced and prestressed concrete bridges have a significantly lower rate of structural deficiency than steel bridges, according to a new PCA analysis.

Material Usage and Condition of Existing Bridges in the U.S. reports that 72,749 of the U.S. bridges studied were structurally deficient. More than half of the deficient bridges were constructed with structural steel.

Market share of the four major bridge construction materials—reinforced concrete, prestressed concrete, structural steel, and timber—in the United States is also analyzed in the report. Not only do concrete bridges have lower rates of deficiencies, but they make up an increasingly larger share of the bridge market. Download the report.

2008 PCA Concrete Bridge Awards Presented

The 2008 winners of the PCA Concrete Bridge Awards were honored on November 2, 2008 at the General Session of the American Concrete Institute Convention. This year’s winners include bridges constructed with cast-in-place concrete, as well as precast concrete, pretensioned concrete beams, and post-tensioned concrete segments. Highway bridges, a railroad bridge, a pedestrian bridge, and an aircraft crossover taxiway are all represented amongst the 2008 award winners.

This eleventh biennial bridge awards competition was co-sponsored by Roads and Bridges Magazine. The jury consisted of three prominent engineers: Myint Lwin (Director, Federal Highway Administration Office of Bridge Technology), Ed Wasserman (Civil Engineering Director, Structures, Tennessee Department of Transportation), and Barney Martin, Jr. (President, Modjeski and Masters, Inc).

More on the bridge award winners.
View the presentation on the award-winning bridges.
View the awards brochure (pdf).

Lane to Manage Bridge Programs

The Portland Cement Association has appointed Susan N. Lane, PE, as program manager for bridges and other transportation structures. She will consult with engineers, contractors, and owners on the use of concrete for highway and railroad bridges, and other transportation structures throughout North America.

Additionally, Lane will be responsible for conducting seminars and publishing materials to assist engineers in the design of concrete bridges and transportation structures, and managing related research and development projects. More about Sue Lane.

Get FREE Registration for World of Concrete and Receive Seminar Discounts

PCA offers free admission to the World of Concrete and discounts on seminars during the 35th annual event. WOC returns to Las Vegas February 2-6, 2009.
Free registration for World of Concrete.