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 17, 2013
Thornton Tomasetti Founding Principal Thornton receives ASCE Lifetime Achievement Award
The OPAL Lifetime Achievement Award is given to civil engineers who “represent a model of achievement to which future generations of engineers aspire to match or exceed.”
| Jan 16, 2013
2013 40 Under 40 application process now open
Building Design+Construction's 40 Under 40 is open to AEC professionals from around the globe.
| Jan 16, 2013
SOM’s innovative Zhengzhou Greenland Plaza opens
The 2.59-million-square-feet building houses a mixed-use program of offices on its lower floors and a 416-room hotel.
| Jan 15, 2013
Morris Architects joins Huitt-Zollars
Morris, which will continue to provide services under its current name and leadership, is entering its 75th year of continuous practice as an architectural, interior design, landscape architecture, and planning firm.
| Jan 11, 2013
HMC Architects: In their own voices
See what HMC professionals say about their “Best AEC Firm to Work For”
| Jan 10, 2013
Guide predicts strongest, weakest AEC markets for 2013
2013 Guide to U.S. AEC markets touts apartments, natural gas, senior housing and transmission and distribution.
| Jan 9, 2013
Panasonic and Bluebeam preview new architect app at CES 2013
Panasonic and Bluebeam Software collaborate to develop and introduce the 4K tablet and software to the design and construction industry.
| Jan 3, 2013
Answered prayers
A bold renovation enables a small church to expand its mission on a grand scale.
| Jan 3, 2013
Top BIM/VDC articles of 2011-2012
A compendium of BD+Cs top building information modeling and virtual design + construction articles from 2011-12.
| Jan 3, 2013
8 trends shaping today’s senior housing
The ranks of those age 65 and older are swelling by the thousands every day. Is there an opportunity for your firm in the seniors housing market?