ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/306852
Photo: Ted Lacey Photography. John S. Dick, Executive Editor 2 | ASPIRE , Fall 2009 E D I T O R I A L Executive Editor: John S. Dick Managing Technical Editor: Dr. Henry G. Russell Managing Editor: Craig A. Shutt Editorial Staff: Daniel C. Brown, Roy Diez Editorial Administration: James O. Ahtes Inc. Art Director: Mark Leader, Leader Graphic Design Inc. Layout Design: Marcia Bending, Leader Graphic Design Inc. Electronic Production: Chris Bakker, Jim Henson, Leader Graphic Design Inc. Ad Sales: Jim Oestmann Phone: (847) 838-0500 • Cell: (847) 924-5497 Fax: (847) 838-0555 firstname.lastname@example.org Reprint Sales: Mark Leader (847) 564-5409 e-mail: email@example.com Publisher: Precast/Prestressed Concrete Institute, James G. Toscas, President Editorial Advisory Board: Susan N. Lane, Portland Cement Association (PCA) John S. Dick, Precast/Prestressed Concrete Institute (PCI) William R. Cox, American Segmental Bridge Institute (ASBI) David McDonald, Epoxy Interest Group (EIG) Dr. Henry G. Russell, Managing Technical Editor POSTMASTER: Send address changes to ASPIrE, 209 W. Jackson Blvd., Suite 500, Chicago, IL 60606. Standard postage paid at Chicago, IL, and additional mailing offices. ASPIrE (Vol. 3, No. 4), ISSN 1935-2093 is published quarterly by the Precast/Prestressed Concrete Institute, 209 W. Jackson Blvd., Suite 500, Chicago, IL 60606. Copyright 2009, Precast/Prestressed Concrete Institute. If you have a project to be con sidered for ASPIrE, send information to ASPIrE, 209 W. Jackson Blvd., Suite 500, Chicago, IL 60606 phone: (312) 786-0300 www.aspirebridge.org e-mail: firstname.lastname@example.org Cover: 4th Street Bridge, Pueblo, Colorado Photo: ©FIGG . Performance of Concrete and Market Share Log on NOW at www.aspirebridge.org and take the ASPIrE Reader Survey. A s ASPIrE™ concludes its second year of exploring sustainable solutions, this issue's PERSPECTIVE by Clifford L. Freyermuth offers a challenge to the nation's bridge officials. In it, he addresses the growing durability of bridges and suggests that the American Association of State Highway and Transportation Officials (AASHTO) and the Federal Highway Administration (FHWA) begin work to require from 100- to 150-year service lives for highway bridges. Such a goal is noteworthy—and achievable. Cliff's career has spanned nearly 55 years. His direct involvement in bridges began with the Arizona State Highway Department in 1958. From there on, it was all concrete when, in 1964, he joined the Portland Cement Association. Then, in 1971, he directed post-tensioning activities for the Prestressed Concrete Institute before founding and managing the Post-Tensioning Institute in 1976. In 1989, he helped establish and then managed the American Segmental Bridge Institute thr ough 2008. He has been instrumental in dealing with many durability and constructability issues that have challenged the prestressed concrete industry since the 1960s. With his unique background, he proposes ways to extend the service life of bridges and advocates the incorporation of minimum service life provisions in the LRFD Specifications. His perspective begins on page 12. Concrete bridges have an enviable performance record. In the United States, statistics on the condition of bridges are kept in the National Bridge Inventory (NBI) maintained by the FHWA. Generally, high-performance concrete for bridges has been widely adopted over the past two decades. As a result, concrete bridges will perform increasingly well in all likelihood, surpassing expectations. Past performance and suggestions for the future are presented in the Perspective feature mentioned above. Another way to measure performance is through the confidence shown by those designing bridges in the materials they select. The percentage of bridges being built of concrete continues to increase. Each year, the FHWA compiles data from the NBI (http://www.fhwa.dot.gov/bridge/nbi/matreport2008. cfm). They publish the quantity and deck areas of all bridges built in a given year, by the material of their superstructures. The data are broken down also by federal and non-federal aid highways and are reported by state. Since it takes nearly 2 years for the NBI to receive data for all new bridges built, the latest complete data released this July was for 2006. The data of interest here are for new and replaced bridges. Rehabilitated bridges are not considered. For the three most recent years, 2004, 2005, and 2006, the percentages of the nation's bridges built using concrete, based on the numbers of projects was 75.8, 76.2, and 75.4, respectively. The balance, of course, is of other materials. Although the percentage of bridges has remained relatively constant, it appears the size of bridge projects using concrete is growing larger, based on the deck areas of bridges built. For concrete, the percentages for the same years are 67.5, 65.5, and 69.3; a dip then significant gr owth. One may also look at the share of bridges built of prestressed concrete. This includes precast, prestressed concrete and all means of prestressing concrete on site such as cast-in-place post-tensioned concrete and all types of segmental concrete construction. The percentages of prestressed concrete bridges built in the past 3 years are by numbers of projects—39.4, 42.5, and 42.9; and by the areas of bridges built—54.8, 55.0, and 60.2. At the same time, in 2006, the number of mildly reinforced concrete bridges exceeded 32% of the total built. These numbers also likely are understated. A bridge's material in the NBI is determined by the material of the main span. A considerable number of bridges are built with a main span of steel and concrete approach spans. Accounting for these additional areas of concrete construction would most certainly add share for concrete. Each day, innovative new solutions are being implemented. In this issue, five such projects are featured; each one employs sustainable design concepts. Each project offers ideas to meet a range of challenges. Consider the 24,000 psi compressive strength concrete (Continued on page 4) Epoxy Interest Group Precast/Prestressed Concrete Institute Portland Cement Association American Coal Ash Association Expanded Shale Clay and Slate Institute Silica Fume Association 1 American Segmental Bridge Institute ASPIRE_fall09.indb 2 9/11/09 2:50:41 PM