Industry Releases Report on Laboratory Testing of Wall Track Anchorage to Concrete

WASHINGTON, D.C., May 31, 2010 - The American Iron and Steel Institute (AISI), Steel Framing Alliance (SFA), and Steel Stud Manufacturers Association (SSMA) Project Monitoring Task Group has published the "Report on Laboratory Testing of Anchor Bolts Connecting Cold-Formed Steel Track to Concrete with Minimum Edge Distances." The report addresses the lack of specific test data to substantiate the need for the reduced design capacities for anchors in concrete for a typical cold-formed steel track to concrete connection loaded parallel to the edge (per ACI 318, Appendix D). It relates to seismic force-resisting systems for cold-formed steel light-framed buildings, which typically comprise shear walls with anchor bolts located at the edge of concrete foundations.

The project was undertaken to evaluate the behavior of the cold-formed steel track-to-concrete anchor bolt connection, establish whether ductile steel failure modes rather than concrete failure modes control the capacity of the connection, and determine if the use of AISI bolt-bearing design values are appropriate for the connection. The primary author was Roger LaBoube, Ph.D., P.E., director of the Wei-Wen Yu Center for Cold-Formed Steel Structures at the Missouri University of Science and Technology.

The experimental testing demonstrated that actual capacities of the track-to-concrete anchor bolt connection far exceed those historically used for design, supporting the use of AISI bolt-bearing design values for the connection in lieu of those determined in accordance with ACI 318, Appendix D. The experimental data demonstrated that ductile steel failure modes rather than concrete failure modes limit the capacity of the connection; therefore, there is no need to require the reduction in the capacity of the connection based on concrete strength as specified in ACI 318, Section D.3.3.6.

A total of 21 tests were performed. All tests were single-bolt tests in cold-formed steel tracks connected to concrete with post-installed steel anchor bolts.

AISI’s codes and standards work is conducted under the Construction Market Council of the Steel Market Development Institute (SMDI), a business unit of AISI. The SMDI oversees the industry’s investment in advancing the case for steel in the marketplace as the preferred material of choice. AISI serves as the voice of the North American steel industry in the public policy arena and plays a lead role in the development and application of new steels and steelmaking technology. AISI is comprised of 24 member companies, including integrated and electric furnace steelmakers, and 138 associate and affiliate members who are suppliers to or customers of the steel industry. AISI's member companies represent approximately 75 percent of both U.S. and North American steel capacity. For more information, visit www.smdisteel.org

The mission of the Steel Framing Alliance is to enable the growth of cold-formed steel framing by identifying, maintaining, and promoting competitive advantages while identifying and preventing preemptive threats. For more information, visit www.steelframing.org.

The Steel Stud Manufacturers Association (SSMA) is the unified voice of the steel framing manufacturing industry. SSMA supports the development and maintenance of quality product standards and specifications, and creates growth opportunities for cold-formed steel through research, marketing and education. For more information, visit www.ssma.com.

Contact:
Debbie Bennett
Manager, Communications
Construction Market
Steel Market Development Institute
Tel: 202.452.7179