DeSimone Consulting Engineers designed the building, using a 12-inch post-tensioned flat-plate concrete floor, which will permit clear spans as long as 40 feet. The flat-plate scheme reduced the floor-to-floor height by more than 3 feet when compared to the original design with composite concrete-steel floors. It also allows floor construction to proceed on a two-day cycle—unprecedented in office building construction. In keeping with safety and security concernsof post 9/11 construction, all means of egress will be protected with 16-inch impact resistant concrete shear walls located in the core of the building. More.

The post-tensioning labor force continues to organize its training and certification through Local 46's Learning Center—an innovative PTI-certified facility with the capacity to train more than 200 post-tensioning installers a year. This, along with project economics, resulted in a milestone in New York City’s residential construction. Kew Gardens, a residential project, is the first post-tensioned residential high-rise in New York City. More.

September PPI: Steel Increases, Ending 6-Month Decline

According to the September Producer Price Index, steel mill products jumped 3.3% in September, reversing a trend of six straight monthly declines. Asphalt prices jumped 4.0% for the month and lumber prices rose 1.9%. Concrete products grew 0.9%.

Since January of 2004 steel prices have increased 32% while concrete prices have risen 15%. Asphalt and lumber have increased 14% and 7% respectively during the same period.

The Department of Labor, Bureau of Labor Statistics, publishes the data.

Student Design Competition Encourages Concrete Thinking

Registration is now open for “Concrete Thinking for a Sustainable World,” a student design competition sponsored by PCA. The contest challenges students to investigate innovative applications of cement-based materials to achieve sustainable design objectives. Designs should illustrate enhanced building performance from the use of cement-based materials and can be an element of the structure or an entire building of modest size. The contest is administered by the Association of Collegiate Schools of Architecture (ACSA) and is open to all ASCA member schools, domestic and international.

The top three designs will share $10,000 in awards and receive a complete package of pcaStructurePoint software. The registration deadline is February 8, 2006, with submissions due May 3. The results will be announced in May 2006.
Download an application

Trump Tower Mat a Record Pour for Self-Consolidating Concrete

On Friday, September 30, workers placed the concrete foundation of Chicago's Trump International Hotel and Tower and set a new record for the single largest pour of self-consolidating concrete in North America.

The 5,000 cubic yard monolithic continuous pour began late Friday morning and lasted 24 hours, according to a news release from Degussa Admixtures, Inc. The firm supplied admixtures for the project and worked with ready mixed concrete supplier Prairie Material Sales on the mix design. The specification called for the use of self-consolidating concrete with a strength of 10,000 psi produced on a continual basis. The foundation is 198 ft. long by 60 ft. wide and 10 ft. deep.

Scheduled for a 2009 completion, Trump International Hotel and Tower will be 92 stories tall with more than 2.6 million square feet of building area. Designers chose a concrete frame and floor system over structural steel to maximize the number of floors while maintaining a lower overall building height.

Self-consolidating concrete is a high-performance concrete that can flow easily into tight and constricted spaces without segregating and without requiring vibration. More.

Earn PDHs with Two New Articles

As part of the Professional Development Series in Structural Engineer, PCA has written two new articles to help fulfill your continuing education requirements. The topics covered include conventional reinforced concrete floor systems as well as post-tensioned flat plate concrete slabs. Just read the articles and take the quiz.
(Click on title to download the PDF.)

Post-Tensioning for Two-Way Flat Plate Construction

Design of Reinforced Concrete Floor Systems

pcaMats and Sub-Grade Modulus

Engineers using pcaMats frequently ask what value should be assumed for the soil sub-grade modulus? This question is best answered by a specialized geotechnical engineer, based on actual data for the soil under the foundations. The PCA publication Concrete Floors on Ground (EB075.03) contains technical information that helps the engineer understand the concept of soil sub-grade modulus and gives guidance as how to determine the modulus for different types of soils. Click here for a tech note on the subject.

Click here to download a trial version of pcaMats. For more on pcaStructurePoint concrete software solutions, click here.

Conference Focuses on Construction Challenge

The Structural Engineers' Buildings Conference & Expo will address one of the major issues facing the nation: how to meet the building needs of a rapidly growing population. The program will feature more than 25 sessions organized into three educational tracks: Code Updates; Design and Analysis; and Project Management. The Expo will be held December 1-2, 2005, at the Fairmont Hotel in Chicago. More.

Free Registration to World of Concrete

The World of Concrete/World of Masonry convenes in Las Vegas January 16-20, 2006. The largest show in concrete features 1,600 exhibitors, 1.3 million square feet of demonstration space, and more than 125 seminars and conference sessions.
More on World of Concrete.
Click here for free registration.

PCI Design Handbook, Precast and Prestressed Concrete - 6th Edition (LT151)

Published by the Precast/Prestressed Concrete Institute, this latest edition has been revised to reflect recent changes in the building codes and standards issued by ASCE, ACI and IBC. The handbook provides easy-to-follow design procedures, newly formatted numerical examples, and both new and updated design aids.