ASTM has released a new HSS standard, A1085 - 13 Standard Specification for Cold-Formed Welded Carbon Steel Hollow Structural Sections (HSS), which will result in the production of improved hollow structural sections (HSS). This specification is a big step forward in simplifying HSS design and usage, thereby making it a more desirable option for HSS.
"We were committed to the development of the new ASTM A1085 specification as it was needed to improve the performance of HSS used in structural applications such as seismic load resisting systems, bridge structures and other dynamically loaded structures," said Brad Fletcher, senior sales engineer with AISC-member Atlas Tube. According to Fletcher, round and square members from 6 in. and up will likely be the main shapes Atlas initially produce under the new specification.
Benefits include:
- Tighter material tolerances and a single minimum yield stress of 50 ksi. Because of the more stringent wall tolerances and the addition of a mass tolerance, it's anticipated that AISC's Committee on Specifications will shortly issue guidelines allowing the full nominal wall thickness can be used for design of HSS. This means no longer needing to reduce the nominal wall thickness by 0.93 as prescribed in the AISC Steel Construction Manual for both member selection and connection design. And more area available for design and a higher minimum yield mean that HSS will become a more economical and efficient design option.
- Maximum specified yield stress of 70 ksi. This will result in a lower expected yield strength for seismic design, and thereby reduce capacity design requirements when HSS are the yielding element. For example, with ASTM A1085 HSS braces in a braced frame, the beams and columns will have lower required strengths. ASTM A1085 is the only HSS specification used in North America or Europe that limits the maximum yield stress.
- Standard requirement for notch toughness. The specification will require all HSS to meet a minimum Charpy V-notch (CVN) value of 25 ft-lb at 40°F, which corresponds to AASHTO Zone 2 requirements. Having the minimum CVN required makes HSS more suitable for use in dynamically loaded structures.
"A1085 makes designing with HSS easier and more efficient for both building and bridge construction," said John Simon, vice president of sales with AISC-member EXLTUBE. "We are hearing a great response from structural engineers who have begun to learn about this new spec through efforts at NASCC: The Steel Conference and other communications, and we're working closely with AISC and the Steel Tube Institute to begin promoting A1085 to our customers. EXLTUBE will be supporting these efforts with inventory as soon as we've determined the sizes the market will require from us."
John Tassone, marketing manager for AISC-member Independence Tube, also commented: "We will be manufacturing and inventorying the product as the need arises," adding that the company will likely concentrate on squares and rounds 4 in. and above to start.
For specific price and availability information, please contact HSS producers and service centers. Contact information is available at www.aisc.org/hss.
About the American Institute of Steel Construction
The American Institute of Steel Construction, headquartered in Chicago, is a not-for-profit technical institute and trade association established in 1921 to serve the structural steel design community and construction industry. AISC's mission is to make structural steel the material of choice by being the leader in structural steel-related technical and market-building activities, including: specification and code development, research, education, technical assistance, quality certification, standardization, and market development. AISC has a long tradition of service to the steel construction industry of providing timely and reliable information.
Related Stories
| Aug 29, 2014
Phifer and Partners to design 'transparent' Museum of Modern Art in Warsaw
The design includes a stage that opens onto the city's Parade Square, so anyone passing by will be able to see performances.
| Aug 29, 2014
China Syndrome: How long will U.S. firms keep milking the Middle Kingdom?
U.S. architecture and engineering firms like Goettsch Partners have been enjoying full employment in China. But will there come a point when Chinese officials—and Chinese designers—say, We can handle this? BD+C's Robert Cassidy digs into this issue.
| Aug 28, 2014
Arthur Platt and Julie Engh to lead AIANY architectural boat tour at BD+C Under40 Leadership Summit
The tour, which will circumnavigate Manhattan, will provide U40 Summit attendees with information about the history and architectural details of numerous buildings visible from the 1920s-era yacht.
| Aug 28, 2014
USGBC, American Chemistry Council join forces to advance LEED
The groups will apply technical and science-based approaches to the LEED green building program.
| Aug 27, 2014
Turkish government orders demolition of residential towers in Istanbul
Citing negative effects to a world heritage site, the Turkish central government has ruled that the recently completed OnaltiDokuz Residence towers must be demolished.
| Aug 27, 2014
Ranked: Top sports facility sector AEC firms [2014 Giants 300 Report]
Populous, AECOM, and Turner head BD+C's rankings of the nation's largest sports facility design and construction firms, as reported in the 2014 Giants 300 Report.
| Aug 27, 2014
Frank Lloyd Wright’s Taliesin school of architecture faces accreditation loss
The Frank Lloyd School of Architecture may be stripped of its ability to confer Master of Architects students based on a revised by-law of the Higher Learning Commission.
| Aug 27, 2014
Survey of NCAA athletic directors reveals strong demand for new facilities, fan amenities
More than 80% of college athletic directors plan to make significant investments in facilities over the next five years to target potential recruits and spectators, according to a new survey by AECOM and Ohio University.
| Aug 27, 2014
Study looks at lessons from involving children in K-12 school design
A study examining what architects can learn from children, especially during the design process, is being carried out through the University of Sheffield's school of architecture.
| Aug 27, 2014
Designs for community-based workspace in Carlsbad unveiled
Cruzan announced make, a 175,000-square-foot office redevelopment project on the coast of Carlsbad, Calif. Cruzan will usher this next generation of community-based, integrated workspace into existence in fall 2014.
