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
| Sep 7, 2014
USGBC + American Chemistry Council: Unlikely partners in green building
In this new partnership, LEED will benefit from the materials expertise of ACC and its member companies. We believe this has the potential to be transformational, writes Skanska USA's President and CEO Michael McNally.
| Sep 7, 2014
Behind the scenes of integrated project delivery — successful tools and applications
The underlying variables and tools used to manage collaboration between teams is ultimately the driving for success with IPD, writes CBRE Healthcare's Megan Donham.
| Sep 7, 2014
Ranked: Top military sector AEC firms [2014 Giants 300 Report]
Balfour Beatty, Fluor, and HDR top BD+C's rankings of the nation's largest military sector design and construction firms, as reported in the 2014 Giants 300 Report.
| Sep 5, 2014
First Look: Zaha Hadid's Grace on Coronation towers in Australia
Zaha Hadid's latest project in Australia is a complex of three, tapered residential high-rises that have expansive grounds to provide the surrounding community unobstructed views and access to the town's waterfront.
| Sep 4, 2014
Ranked: Top courthouse sector AEC firms [2014 Giants 300 Report]
Fentress Architects, Tutor Perini, and AECOM top BD+C's rankings of design and construction firms with the most revenue from courthouse facilities, as reported in the 2014 Giants 300 Report.
| Sep 4, 2014
Hospital CEOs, architects sound off on state of healthcare design
Healthcare construction will continue to feel the effects of radical changes in the delivery of care, according to healthcare leaders attending the annual Summer Leadership Summit of the American College of Healthcare Architects and the AIA Academy of Architecture for Health.
| Sep 4, 2014
Best of education design: 11 projects win AIA CAE architecture awards [slideshow]
The CAE Design Excellence Award honors educational facilities that the jury believes should serve as an example of a superb place in which to learn. Projects range from a design school in Maryland to an elementary school in Washington.
Sponsored | | Sep 4, 2014
Learning by design: Steel curtain wall system blends two school campuses
In this the new facility, middle school and high school classroom wings flank either side of the auditorium and media center. A sleek, glass-and-steel curtain wall joins them together, creating an efficient, shared space. SPONSORED CONTENT
| Sep 4, 2014
Strong industry growth could be slowed by skilled labor shortage, says Gilbane report
While construction spending for 2014 will finish the year 5.5% higher than 2013 and the unemployment rate in construction is down to 7.5%, the industry has been losing workers for more than five years, according to a new Gilbane report.
| Sep 3, 2014
Ranked: Top local government sector AEC firms [2014 Giants 300 Report]
STV, HOK, and Turner top BD+C's rankings of the nation's largest local government design and construction firms, as reported in the 2014 Giants 300 Report.