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
| Apr 14, 2011
USGBC debuts LEED for Healthcare
The U.S. Green Building Council (USGBC) introduces its latest green building rating system, LEED for Healthcare. The rating system guides the design and construction of both new buildings and major renovations of existing buildings, and can be applied to inpatient, outpatient and licensed long-term care facilities, medical offices, assisted living facilities and medical education and research centers.
| Apr 13, 2011
National Roofing Contractors Association revises R-value of polyisocyanurate (ISO) insulation
NRCA has updated their R-value recommendation for polyisocyanurate roof insulation with the publication of the 2011 The NRCA Roofing Manual: Membrane Roof Systems.
| Apr 13, 2011
Professor Edward Glaeser, PhD, on how cities are mankind’s greatest invention
Edward Glaeser, PhD, the Fred and Eleanor Glimp Professor of Economics at Harvard University and director of the Taubman Center for State and Local Government and the Rappaport Institute for Greater Boston, as well as the author of Triumph of the City: How Our Greatest Invention Makes Us Richer, Smarter, Healthier, and Happier, on how cities are mankind’s greatest invention.
| Apr 13, 2011
Southern Illinois park pavilion earns LEED Platinum
Erin’s Pavilion, a welcome and visitors center at the 80-acre Edwin Watts Southwind Park in Springfield, Ill., earned LEED Platinum. The new 16,000-sf facility, a joint project between local firm Walton and Associates Architects and the sustainability consulting firm Vertegy, based in St. Louis, serves as a community center and special needs education center, and is named for Erin Elzea, who struggled with disabilities during her life.
| Apr 13, 2011
Virginia hospital’s prescription for green construction: LEED Gold
Rockingham Memorial Hospital in Harrisonburg, Va., is the commonwealth’s first inpatient healthcare facility to earn LEED Gold. The 630,000-sf facility was designed by Earl Swensson Associates, with commissioning consultant SSRCx, both of Nashville.
| Apr 13, 2011
Office interaction was the critical element to Boston buildout
Margulies Perruzzi Architects, Boston, designed the new 11,460-sf offices for consultant Interaction Associates and its nonprofit sister organization, The Interaction Institute for Social Change, inside an old warehouse near Boston’s Seaport Center.
| Apr 13, 2011
Expanded Museum of the Moving Image provides a treat for the eyes
The expansion and renovation of the Museum of the Moving Image in the Astoria section of Queens, N.Y., involved a complete redesign of its first floor and the construction of a three-story 47,000-sf addition.
| Apr 13, 2011
Duke University parking garage driven to LEED certification
People parking their cars inside the new Research Drive garage at Duke University are making history—they’re utilizing the country’s first freestanding LEED-certified parking structure.
| Apr 13, 2011
Red Bull Canada HQ a mix of fluid spaces and high-energy design
The Toronto architecture firm Johnson Chou likes to put a twist on its pared-down interiors, and its work on the headquarters for Red Bull Canada is no exception. The energy drink maker occupies 12,300 sf on the top two floors of a three-story industrial building in Toronto, and the design strategy for its space called for leaving the base building virtually untouched while attention was turned to the interior architecture.
| Apr 13, 2011
Former department store gets new lease on life as MaineHealth HQ
The long-vacant Sears Roebuck building in Portland, Maine, was redeveloped into the corporate headquarters for MaineHealth. Consigli Construction and local firm Harriman Architects + Engineers handled the 14-month fast-track project, transforming the 89,000-sf, four-story facility for just $100/sf.
