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
| Nov 22, 2013
Kieran Timberlake, PE International develop BIM tool for green building life cycle assessment
Kieran Timberlake and PE International have developed Tally, an analysis tool to help BIM users keep better score of their projects’ complete environmental footprints.
| Nov 20, 2013
Architecture Billings Index slows in October; project inquiries stay strong
Following three months of accelerating demand for design services, the Architecture Billings Index reflected a somewhat slower pace of growth in October. The October ABI score was 51.6, down from a mark of 54.3 in September.
| Nov 19, 2013
Pediatric design in an adult hospital setting
Freestanding pediatric facilities have operational and physical characteristics that differ from those of adult facilities.
| Nov 18, 2013
6 checkpoints when designing a pediatric healthcare unit
As more time and money is devoted to neonatal and pediatric research, evidence-based design is playing an increasingly crucial role in the development of healthcare facilities for children. Here are six important factors AEC firms should consider when designing pediatric healthcare facilities.
| Nov 18, 2013
Lord Aeck Sargent opens metro D.C. office, updates brand
Architecture, design, and planning firm unveils its sixth office, plus a new visual identity system and website
| Nov 18, 2013
How do construction professionals use social media?
LinkedIn is the social network used by most construction professionals, according to the results of a newly released national survey conducted by the Construction Marketing Association.
| Nov 17, 2013
How to spend your first 15 minutes with a prospect
Every business development person has been there. You’ve finally earned a few minutes to impress a prospect that you’ve been pursuing. This is your opportunity to shine. What do you say?
| Nov 17, 2013
Meet up with the BD+C team at Greenbuild. Drinks are on us!
To all our friends in the AEC industry, you are cordially invited to join the BD+C team at several fun events during the Greenbuild show this week. No RSVP required. Just show up and enjoy.
| Nov 15, 2013
Halls of ivy keep getting greener and greener
Academic institutions have been testing the limits of energy-conserving technologies, devising new ways to pay for sustainability extras, and extending sustainability to the whole campus.
| Nov 15, 2013
Pedia-Pod: A state-of-the-art pediatric building module
This demonstration pediatric treatment building module is “kid-friendly,” offering a unique and cheerful environment where a child can feel most comfortable.