Working Together Is a Recipe for Success

The Wacker Drive Reconstruction in Chicago, Ill. is an excellent example of how good teamwork and communication can lead to a successful project. Told from the perspectives of the owner, construction manager, general contractor, and concrete supplier, the story appeared in the 27th issue of HPC Bridge Views.

The owner, Chicago Department of Transportation, had the new structure designed for a minimum service life of 75 years to faithfully serve the citizens of Chicago into the 22nd century. The construction manager explains how teamwork helped overcome many challenges faced during construction—pumping, placing, finishing, and controlling air content of HPC. “Though the start was a little rough,” the contractor related, “working with HPC was no different from any other concrete.” The material supplier found the HPC mix required considerably more attention to material testing, production, and delivery. But, as he states, the result "is an impressive structure that should not require reconstruction for many years to come."

Download the full story.
Past issues of HPC Bridge Views.

HPC Bridge Program Gets Boost from SAFETEA-LU

The $286.4-billion new highway bill known as SAFETEA-LU—short for Safe, Accountable, Flexible, and Efficient Transportation Equity Act: A Legacy for Users, has authorized $16.5 million for the High-Performance Concrete Bridge Program consisting of research and technology transfer. NCBC is working closely with FHWA to design a program to implement HPC throughout the United States and make it a routine practice for all bridges in the next four years.

More information to come in an upcoming issue of HPC Bridge Views.

Deadline for Entries Is March 31

The tenth biennial Bridge Awards Competition, co-sponsored by PCA and Roads & Bridges magazine, recognizes excellence in design and construction of concrete bridges. Entries are encouraged for cast-in-place or precast concrete bridges with short, medium, or long spans. Newly constructed, reconstructed, or widened structures qualify for the competition. There is no fee for entry, and public and private organizations may submit as many bridges as desired.

Entries are due March 31, 2006. Click here for entry form.
For more information, contact Shri Bhide at PCA 847.972.9100.

Early Registration for CBC Ends April 7

The 2006 Concrete Bridge Conference will be held May 7-10, 2006 at the Nugget Resort Hotel in Reno, Nev. in conjunction with the 2006 Post-Tensioning Institute (PTI) Technical Conference and Exhibition. Take advantage of early registration rates. More registration information.

A special program, "20 Years of Silica-fume Concrete Bridge Decks – What have we learned?" is scheduled for Tuesday May 9. Silica-fume high-performance concrete (HPC) is now widely used in the United States for durable bridge deck construction. The properties of HPC require each project participant to adhere to good specifications and construction practices to assure the durable benefits are achieved. A nation-wide panel of leading state, design, producer, and contractor representatives will discuss field experiences and solutions to items leading to successful construction and performance of silica-fume HPC bridge decks. This hot-topic program will feature brief presentations by the panel, followed by a question and answer session .

Design of Concrete Bridges by the AASHTO LRFD

The 8th annual Bridge Professors' Seminar is scheduled for August 5-6, 2006 at PCA in Skokie, Ill. These seminars provide information on the latest concrete industry developments to university professors so that they can introduce new courses or update existing ones in concrete design at their universities.

By 2007, all bridges receiving federal funding must be designed by AASHTO’s new LFRD Bridge Design Specifications. The seminar's emphasis is on the new state-of-the-art design methods in the LRFD Specifications that are significantly different than the current methods in the Standard Bridge Design Specifications. As in the past, there is no seminar registration fee and the travel is typically sponsored by our regional cement and concrete promotion partners.

For information, please contact Caron Johnsen, 847.972.9058, or Basile Rabbat,
847.972.9062 at PCA.

Purchase 3 Bridge Design Resources and Save

Build your bridge library by purchasing AASHTO LRFD Design of Cast-in-Place Concrete Bridges (EB232), AASHTO LRFD Strut-and-Tie Model Design Examples (EB231), and Guide Specification for High Performance Concrete for Bridges (EB233)and save $25.
XC124 —$60

With HPC, should I specify compressive strength at 56 days rather than the traditional age of 28 days?

Answer:
The use of a 56-day age for the measurement of concrete compressive strength was introduced into the building industry many years ago. The primary application was cast-in-place columns for high-rise buildings. For structural purposes, columns only receive their full design load after the building is finished and occupied. Since it takes many months to build a high-rise building, the concrete design strength is not needed until an age much later than 28 days. An age of 56 days is selected for most projects with an age of 90 days being used occasionally. From an economic viewpoint, this means that the same concrete mix can be used for a higher design strength because of the strength gain that occurs between 28 and 56 days. This is particularly important when a mineral admixture such as fly ash is used. More.