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 17, 2014
New hub on campus: Where learning is headed and what it means for the college campus
It seems that the most recent buildings to pop up on college campuses are trying to do more than just support academics. They are acting as hubs for all sorts of on-campus activities, writes Gensler's David Broz.
Sponsored | | Sep 17, 2014
The balance between innovation and standardization – How DPR Construction achieves both
How does DPR strike a balance between standardization and innovation? In today’s Digital COM video Blog, Sasha Reed interviews Nathan Wood, Innovator with DPR Construction, to learn more about their successful approach to fueling innovation. SPONSORED CONTENT
| Sep 16, 2014
Ranked: Top hotel sector AEC firms [2014 Giants 300 Report]
Tutor Perini, Gensler, and AECOM top BD+C's rankings of design and construction firms with the most revenue from hospitality sector projects, as reported in the 2014 Giants 300 Report.
| Sep 16, 2014
Studies reveal growing demand for LEED-credentialed professionals across building sector
The study showed that demand for the LEED Accredited Professional and LEED Green Associate credentials grew 46 percent over a 12-month period.
| Sep 16, 2014
Shigeru Ban’s design wins Tainan Museum of Fine Arts competition
Pritzker Prize-winning architect Shigeru Ban has won an international competition organized by The Tainan Museum of Art in Taiwan. Ban's design features cascading volumes with an auditorium, classrooms, and exhibition galleries.
| Sep 16, 2014
Competition asks architects, designers to reimagine the future of national parks
National Parks Now asks entrants to propose all types of interventions for parks, including interactive installations, site-specific education and leisure opportunities, outreach and engagement campaigns, and self-led tours.
| Sep 15, 2014
Sustainability rating systems: Are they doomed?
None of the hundreds of existing green building rating systems is perfect. Some of them are too documentation-heavy. Some increase short-term project cost. Some aren’t rigorous enough or include contentious issues, writes HDR's Michaella Wittmann.
| Sep 15, 2014
Ranked: Top international AEC firms [2014 Giants 300 Report]
Parsons Brinckerhoff, Gensler, and Jacobs top BD+C's rankings of U.S.-based design and construction firms with the most revenue from international projects, as reported in the 2014 Giants 300 Report.
| Sep 15, 2014
Argentina reveals plans for Latin America’s tallest structure
Argentine President Cristina Fernández de Kirchner announces the winning design by MRA+A Álvarez | Bernabó | Sabatini for the capital's new miexed use tower.
| Sep 15, 2014
Perkins+Will unveils design for Ghana's largest hospital
The new hospital will be home to numerous hospital services including public health, accident and emergency, imaging, obstetrics, gynecology, dental, surgical, intensive care and administration.