How familiar are you with the LRFD?

As of October 1, 2007, all bridges receiving federal funding will have to be designed by the LRFD specifications. PCA will conduct a one-day seminar on designing concrete bridges by the LRFD specifications on May 25, 2007 at our headquarters in Skokie, Ill. The seminar emphasizes the new state-of-the-art design methods in the LRFD specifications that are significantly different than the current ones in the Standard specifications. Seminar attendees will be awarded 6.5 PDHs. For more information and to register.

Guadalupe County I-40 Overpass Bridges Welcome Visitors

These routine highway overpass structures have a unique role – they help welcome visitors to Guadalupe County and to the state of New Mexico. As such, aesthetics were a priority throughout the planning and construction process of the three two-span continuous precast, prestressed concrete bridges. Southwestern-style artwork was incorporated into the MSE walls, wingwalls, piers, and barrier rail.

To minimize fill requirements and to maintain the necessary under clearance, four 54-inch U-beams were selected in lieu of five 63-inch I-beams for the typical span of 105 feet 8 inches. Judicious use of high strength, high performance concrete, prestressing strands in the top flanges of the beams, spread footings, and semi-integral abutments resulted in economical, durable, and pleasing structures.

A winner of the 2006 Concrete Bridge Awards, the jury's comments were: "An interesting use of Southwest-type motif, innovative form liners, smooth girder lines, and clever use of MSE walls, wing walls and stub walls, and prudent design has resulted in aesthetically pleasing, structurally efficient, economical, and durable bridges."

Read about all the 2006 winners.

What is Service Life and How is it Predicted?

AASHTO’s LRFD Bridge Design Specifications define service life as the period that a bridge is expected to be in service. And, the design life is defined as the period that the transient loads are expected not to exceed the nominal value. Though the specifications specify a design life of 75 years, they are silent on the target value for the service life. More.

Read more Q&As on HPC.

Call for Abstracts for 2008 CBC

The National Concrete Bridge Council is pleased to announce the 2008 Concrete Bridge Conference to be held May 4-6, 2008 at the Hyatt Regency in St. Louis, Mo. CBC has quickly become the premier national venue for the exchange of ideas and information on all aspects of concrete bridge design and construction. Typically, more than 300 bridge engineers including FHWA, DOT, and consulting engineers, academia, contractors, and industry attend CBC. It is being held in conjunction with the 2008 Post-Tensioning Institute (PTI) Technical Conference and Exhibition. Your registration will enable you to attend both conferences.

Abstracts are due July 15. More.

The 2006 Conference Bridge Proceedings, featuring more than 90 papers, are available on a CD. More.

Material Property Characterization Of Ultra High-Performance Concrete

The U.S. Federal Highway Administration (FHWA) has released a report that explores the material behaviors of one ultra high-performance concrete (UHPC) in terms of accepted concrete testing methodologies. The FHWA has been investigating the optimal use of UHPC in highway bridges, and this report presents results from the first phase of this research program. More.

Effect of Superstructure Flexibility on Bridge Deck Durability

A research project recently completed at the University of Illinois, Urbana–Champaign employed an extensive literature review, study of bridges in the field, and a computational finite element model, to synthesize a variety of issues that relate "steel vs. concrete" girder properties to the deterioration of bridge decks to help determine why decks supported on concrete girder perform better than similar decks supported on steel girders. The research was sponsored by the Portland Cement Association. More.

The National Ready Mixed Concrete Association’s 2007 Concrete Technology Forum: Focus on High Performance Concrete will be held May 22-24, 2007 in Dallas. The forum will bring researchers and practitioners together to discuss the latest advances, technical knowledge, continuing research, tools and solutions for high performance concrete. PCA is an organizational partner of the 2007 CTF.

The First International Conference on Recent Advances in Concrete Technology (rac07) will be held September 19-21, 2007, at the Sheraton in Crystal City, Va. The conference is being organized by the University of Maryland, Howard University, and CI-Premier PTE Ltd of Singapore, and co-sponsored by PCA.