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
| Jan 27, 2012
Columbia University’s New Core Laboratory aims for LEED Silver
Construction manager Sordoni Construction Co. along with the design team of Payette Architects and Vanderweil Engineers will provide design and construction services to renovate the majority of the existing Core Lab building to create the new Lamont Center for Bio-Geochemistry.
| Jan 26, 2012
Three dead, 16 missing in Rio buildings collapse
The buildings, one 20 floors high, collapsed on Wednesday night in a cloud of dust and smoke just one block away from the city's historic Municipal Theater.
| Jan 26, 2012
Siemens launches smoke detection knowledge center
New knowledge center web site demonstrates efficacy of smoke detection.
| Jan 26, 2012
Hendrick Construction completes Osso Restaurant in Charlotte
Designed by François Fossard, Osso's upscale interior includes tapered, twisted decorative columns and an elegant fireplace in the center of the lounge.
| Jan 26, 2012
HOK partners with USGBC on design of Haiti children's center
Passive design principles give form to a sustainable, restorative environment for the children of Haiti.
| Jan 26, 2012
American Standard names Gould as president and CEO
Gould succeeds Don Devine, who led the successful turnaround of American Standard Brands.
| Jan 26, 2012
Summit Design+Build completes law office in Chicago
Applegate & Thorne-Thomsen's new office suite features private offices, open office area, conference rooms, reception area, exposed wood beams and columns, and exposed brick.
| Jan 24, 2012
New iPad app ready for prime time
Siemens’ versatile application connects users to APOGEE BAS control and monitoring functions via wireless network connectivity. The application directly interacts with BACnet/IP and Siemens APOGEE P2 field panels.
| Jan 24, 2012
Vyhanek joins Thornton Tomasetti’s Kansas City office
Vyhanek will assemble a new MEP team in the Midwest to support Building Performance and Property Loss Consulting practices.
| Jan 24, 2012
U of M installs new lighting at Crisler Player Development Center
Energy efficient lighting installed at PDC reduce costs and improves player performance.
