THE CONCRETE BRIDGE MAGAZINE

SUMMER 2013

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.

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Portland Cement Association Do Not Let the Perfect Be the Enemy of Good W hen an engineer tries something new, there is a series of questions that will be asked by others involved (and sometimes those not involved) in the project. • Is this change really going to simplify things? • Will this change really save that much money? • Is this procedural change going to add value to the final project? • Why change if the current approach has worked for years? In September 2011, as the retiring Tennessee state bridge engineer, Ed Wasserman presented a paper titled "Reflections or Fiction and Fact from Ed's Almanac." The main thrust of his reflection was the many opportunities he enjoyed through learning and sharing with others about changes in bridge technologies (see the ASPIRE TM website, under Resources/Papers, for a copy of Wasserman's paper). He goes on to say, bridge engineers should be brave but must also be smart. He reminds us all to never become just a number checker, and to always step back and evaluate the new concept for fundamental- and advanced-stage flaws. My goal with this editorial is to keep his advice in the forefront. When evaluating new concepts and technologies, we all need to ask ourselves: • Is this change an appropriate risk? • What is the consequence of exceeding the limits? • Does there need to be redundancy (multiple levels of protection) in the member's durability? • If this change has a flaw, will it always meet the belt-and-suspenders strength limit state? • Will the transient overloading from a superload cause an exceedance affecting the serviceability of this new detail? • Is there adequate redundancy in the load path? • Or, is there enough excess capacity above all factored loads? Voltaire was the pen name of a French philosopher named François-Marie Arouet who lived from 1694 to 1778. According to Wikipedia, "the phrase 'The perfect is the enemy of good' is an aphorism or proverb meaning that insisting on perfection often results in no improvement at all." The phrase is commonly attributed to Voltaire's moral poem, La Bégueule. Judiciously taking design codes and applying these design principles is always an engineer's professional responsibility. But how the engineer sequences the construction and selects details is how the concrete bridge industry advances every day. New equipment and new materials are changing the tools available to engineers to deliver every infrastructure project. During my career as a state bridge engineer, I had the chance to look at in-service bridge problems and major construction challenges. In every case, it took multiple issues to cause the problem. There was never a single root cause for the challenge. Recently, I attended a meeting of the AASHTO T-10 committee on Concrete Design where committee members were working to ballot additions and changes to the 2014 (and beyond) AASHTO LRFD Bridge Design Specifications. These specification changes will certainly offer more high-performance concrete choices to industry suppliers, designers, contractors, and owners. Today, bridge engineers have dramatically more choices to address our nation's bridge inventory. Please, do not let the perfect be the enemy of good. Photo: PCI. William Nickas, Editor-in-Chief 2 | ASPIRE , Summer 2013 E D I T O R I A L 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 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 Paducah & Louisville Railway Bridge J23.3 near Fort Knox, Ky. Photo: Alfred Benesch & Co. 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 Postmaster: Send address changes to ASPIRE, 200 W. Adams St., Suite 2100, Chicago, IL 60606. Standard postage paid at Chicago, IL, and additional mailing offices. ASPIRE (Vol. 7, No. 3), ISSN 1935-2093 is published quarterly by the Precast/ Prestressed Concrete Institute. Copyright 2013, Precast/Prestressed Concrete Institute. If you have a project to be con sidered 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 American Segmental Bridge Institute Epoxy Interest Group Silica Fume Association Expanded Shale Clay and Slate Institute American Shotcrete Association Post-Tensioning Institute Precast/Prestressed Concrete Institute Book_Sum13.indb 2 7/1/13 6:55 AM

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