THE CONCRETE BRIDGE MAGAZINE

SUMMER 2014

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/335723

Contents of this Issue

Navigation

Page 3 of 49

EDITORIAL Technique is Cheap William Nickas, Editor-in-Chief In the Winter 2014 issue of ASPIRETM, Dr. Henry Russell commented in his editorial about specifications related to concrete materials and designing for service life. The editorial caused several readers to comment on the need for better service life prediction models for structures and their materials. In my Spring editorial, a futurist helped set the tone for the benefits of extending our thinking and moving beyond our engineering and construction constraints. In this issue, we want to continue to think in the future tense. The Perspective in this issue is by Dr. Ben Graybeal of the Federal Highway Administration. In it, he examines the motivation for much of the past research on concrete materials. Given significant progress in the past several decades, Graybeal cautions of the risk to not engage the research community in a new level of challenges. He concludes by proposing four key topics that he sees as ripe for a strategic investment of research capital. Read his article beginning on page 10. I took notice of an article about an avalanche of debate created by a statement by Harvey Littleton at a conference in 1972. Littleton is the son of Dr. Jesse T. Littleton, renowned director of research for Corning Glass Works and inventor of Pyrex glassware. Littleton commented, “Technique is cheap.” To calm the debate, Littleton later stated, “All I meant by that is technique is available to everybody, that you can read technique, if you have any background. Technique in and of itself is nothing. But technique in the hands of a strong creative person takes on another dimension.” Strong creative engineers together with experienced and talented contractors can reshuffle the deck on how bridges are developed and delivered. Such teams create concepts for alternatives from which the best evolve to meet the requirements of a project. The challenges can be a large program of bridges for a state such as we’ve seen in Missouri or Pennsylvania or just a single off-system bridge found in every community in the nation. These system approaches often introduce new levels of complexity. When bridges are built in the traditional way— piece by piece—the construction sequence allows some relief and redistribution of stresses during assembly. Complex systems approaches can lock in stresses during construction, which together with restrained thermal movements, may introduce significant stresses in the structure. One of Graybeal’s proposed research topics involves this issue. We have many techniques available to us to address the challenges created through today’s more sophisticated structural demands and solutions. As Littleton said, “… technique in the hands of a strong creative person takes on another dimension.” Concrete is the ideal material for the nation’s infrastructure. It is capable of assuming practically any shape. Today’s materials technology allows superior durability and longevity. And still, we are finding astonishing new ways of refining the materials and new methods of construction such as • hardening vulnerable locations like girder ends and pier caps under expansion joints, • utilizing compressed concrete in vulnerable locations to increase long-term durability, • providing multiple levels of protection in the newest post-tensioning systems, • integrating use of high-performance and ultra-high­strength materials at connections, and • layering technologies using resilient, impermeable materials at the riding surface so that bridge decks can reach a 100-year service life even on salted northern highways. Let’s dare to dream. As Graybeal concludes, “Visionary research can propel us through another century of concrete innovation.” Editor-in-Chief William Nickas • wnickas@pci.org Managing Technical Editor Dr. Henry G. Russell Program Manager Nancy Turner • nturner@pci.org Associate Editors Emily B. Lorenz Craig A. Shutt Art Director Paul Grigonis Layout Design Casey Braun Tressa A. Park Editorial Advisory Board William Nickas, Precast/Prestressed Concrete Institute William R. Cox, American Segmental Bridge Institute Dr. David McDonald, Epoxy Interest Group Dr. Henry G. Russell, Henry G. Russell Inc. Cover The Putnam Bridge in Washington County, Ohio, is a testament to the timeless aesthetic of concrete bridges. For more information on Washington County’s bridges, see the feature on page 38. Ad Sales Jim Oestmann Phone: (847) 838-0500 Cell: (847) 924-5497 Fax: (847) 838-0555 joestmann@arlpub.com Reprints Paul Grigonis • pgrigonis@pci.org Publisher Precast/Prestressed Concrete Institute James G. Toscas, President Epoxy Interest Group Expanded Shale Clay and Slate Institute Portland Cement Association Post-Tensioning Institute Precast/Prestressed Concrete Institute ASPIRE (Vol. 8, No. 3), ISSN 1935-2093 is published quarterly by the Precast/ Prestressed Concrete Institute. Copyright 2014, Precast/Prestressed Concrete Institute. If you have a project to be considered for ASPIRE, send information to ASPIRE 200 W. Adams St., Suite 2100 • Chicago, IL 60606 phone: (312) 786-0300 www.aspirebridge.org e-mail: info@aspirebridge.org

Articles in this issue

Links on this page

Archives of this issue

view archives of THE CONCRETE BRIDGE MAGAZINE - SUMMER 2014