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
| Dec 17, 2014
USGBC announces 2014 Best of Green Schools honorees
Houston's Monarch School was named the K-12 school of the year, and Western Michigan University was honored as the top higher-ed institution, based on environmental programs and education efforts.
| Dec 17, 2014
ULI report looks at growing appeal of micro unit apartments
New research from the Urban Land Institute suggests that micro units have staying power as a housing type that appeals to urban dwellers in high-cost markets who are willing to trade space for improved affordability and proximity to downtown neighborhoods.
| Dec 17, 2014
11 predictions for high-rise construction in 2015
In its annual forecast, the Council on Tall Buildings and Urban Habitat predicts that 2015 will be the "Year of the Woodscraper," and that New York’s troubled B2 modular high-rise project will get back on track.
| Dec 17, 2014
Demand softens, but outlook for Architecture Billings Index remains positive
The AIA's Architecture Billings Index for November was 50.9, down from a mark of 53.7 in October. Despite the drop, the ABI continued its seven-month run of positive scores (above 50).
Sponsored | | Dec 16, 2014
Quadcopters save project team $15K in warranty work
On a recent trip to see what technology Todd Wynne and the rest of the team at Rogers-O’Brien Construction have been tinkering with, I had a chance to experience firsthand which new hardware innovations will one day be applied in the AEC space.
| Dec 16, 2014
Architect Eli Attia sues Google over tall building technology
Attia and tech company Max Sound Corp. have brought a lawsuit against Google because of Flux, a Google X-developed startup launched in 2014. Flux creates software to design environmentally-friendly buildings in a cost-effective way.
| Dec 15, 2014
SHoP Architects plans to turn NY's Seaport District into pedestrianized, mixed-use area
The scheme includes a proposed 500-foot luxury residential tower that would jut out into the harbor, extending the Manhattan grid out into the waterfront.
| Dec 15, 2014
Frank Lloyd Wright School of Architecture launches fundraising campaign for independent incorporation
The Frank Lloyd Wright Foundation announced today that it approved a possible path toward independent incorporation of the Frank Lloyd Wright School of Architecture by raising $2 million before the end of 2015.
| Dec 15, 2014
Studio Gang tapped for American Museum of Natural History expansion
Chicago-based Studio Gang Architects has been commissioned to design the $325 million Gilder Center for Science, Education and Innovation at the American Museum of Natural History in New York.
| Dec 12, 2014
Dunkin’ Donuts launches certification for green restaurant buildings
The company aims to build 100 new DD Green-certified restaurants by the end of 2016.
