ACI Criteria Paves Way
for Post-Tensioned Wall System
A special ACI task force recently approved specifications and testing guidelines that will allow the introduction of a new concrete structural system—post-tensioned shear walls—for seismic design of buildings.

"The introduction of new innovative concrete systems to resist seismic and wind forces is very rare," says PCA Attilla Beres, who served on the ACI task group. "Now, with the use of post-tensioning, efficient concrete shear walls will be added to the engineers' palette of options."

Concrete systems for lateral resistance used in seismic design currently are limited to shear walls and moment-resisting frame, explains Beres. Expanding post-tensioning technology to include shear walls helps give concrete an edge over structural steel.

The use of the system is not limited to seismically active areas. With the adoption of new national codes, projects in areas previously regarded as low or moderate zones can be subject to the same provisions.

This ACI acceptance criteria includes performance specifications and testing guidelines that will allow building departments to approve the system. The next steps, says Beres, are development of design guidelines and adoption into the ACI building code.
Contact Attila Beres

FDR Recycles 'The Kanc'
A landmark New Hampshire highway served as a showcase for the state's first Full-Depth Reclamation (FDR) project using cement.

State Route 112 in the White Mountain National Forest, called the Kancamagus Highway or The Kanc, was recently dedicated by the U.S. Forest Service as one of America’s Scenic Byways. It was also the site of a seminar and construction tour conducted by Northeast Cement Shippers Association to demonstrate the benefits of FDR for recycling failed asphalt pavements.

Held June 21 in Loon Mountain, the seminar featured a brief classroom session followed by a tour of a 1000-foot section of the highway under reconstruction. On this test section, the old asphalt and base materials were pulverized in-place on the roadway, mixed with cement and water, and then compacted to produce a new base.

With funds provided by the Recycled Materials Research Center, the University of Massachusetts, and the USDA Forest Service, researchers will perform field tests on this section for an ongoing study on FDR subjected to early traffic and frost.
Contact Greg Halsted

May PPI: Steel Continues
Descent, But from Dizzying Heights
According to the May Producer Price Index (PPI), steel prices declined 2.0% in May, the fourth straight monthly decline. Lumber prices also declined, dropping 3.9% for the month. Concrete products rose a modest 0.1%, while asphalt grew 1.9% in May.

Over the past 12 months concrete prices have risen 10.2% while steel and asphalt have grown 9.2% and 7.3% respectively. Lumber has declined 8.1% over the period. However, compared to January 2004, steel prices are 39% higher, concrete prices are 12% higher and asphalt and lumber prices are 9% and 7% higher, respectively.

The Department of Labor, Bureau of Labor Statistics, publishes these data. They are provided by PCA market research to aid in the promotion of concrete and cement-based products.
Contact Craig Schulz

Homeland Security Issues Mounting
Although opposed by many in the construction and design community, the push to develop building codes and standards to address homeland security threats is gaining momentum and even broadening in scope.

At a recent meeting of American Society for Testing and Materials (ASTM) Committee E54 on Homeland Security, committee members considered expanding its work to include state or local government buildings, which may become targets as more federal facilities are hardened to resist attacks. Also of concern are buildings adjacent to protected federal facilities. In addition to addressing this broader concept of homeland security for blast, vehicular, ballistic,and forced entry, ASTM is also developing criteria for arson and incendiary threats.
Contact Steve Szoke

Lou Jany, Essroc Cement, is president of the Saylor Cement Kilns Preservation Society.
Visit the Web site at www.saylorcementkilns.org
Contact Lou Jany at Essroc

ASTM Honors Kosmatka
The ASTM International's Committee C01 on Cement has awarded an honorary membership to Steve Kosmatka in recognition of his outstanding service to the committee and the cement industry. Kosmatka heads PCA's research, technical, and educational programs as Staff Vice President, Research and Technical Services.
Contact Steve Kosmatka.

Skokie Courses

Concrete: Principles and Practice
October 10-13, 2005


Microscopy of Clinker
and Cement
October 31-November 4, 2005

Troubleshooting: Solutions to Concrete Field Problems
November 14-16, 2005

Mill Grinding
October 17-19, 2005

Kiln Process
October 3-6, 2005