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 40Ā°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 13, 2014
6 legislative actions to ignite the construction economy
The American Institute of Architects announced its āpunch listā for Congress that, if completed, will ignite the construction economy by spurring much needed improvements in energy efficiency, infrastructure, and resiliency, and create jobs for small business.
| Jan 12, 2014
CES showcases innovations: Can any of these help you do your job better?
The Consumer Electronics Show took place this past week in Las Vegas. Known for launching new products and technologies, many of the products showcased there set the bar for future innovators. The show also signals trends to watch in technology applicable to the design and building industry.Ā
| Jan 12, 2014
The āfuzz factorā in engineering: when continuous improvement is neither
The biggest threat to human life in a building isnāt the potential of natural disasters, but the threat of human error. I believe itās a reality that increases in probability every time a code or standard change is proposed.Ā
| Jan 12, 2014
5 ways virtual modeling can improve facilities management
Improved space management, streamlined maintenance, and economical retrofits are among the ways building owners and facility managers can benefit from building information modeling.
| Jan 11, 2014
Getting to net-zero energy with brick masonry construction [AIA course]
When targeting net-zero energy performance, AEC professionals are advised to tackle energy demand first. This AIA course covers brick masonry's role in reducing energy consumption in buildings.Ā
| Jan 10, 2014
What the states should do to prevent more school shootings
To tell the truth, I didnāt want to write about the terrible events of December 14, 2012, when 20 children and six adults were gunned down at Sandy Hook Elementary School in Newtown, Conn. I figured other media would provide ample coverage, and anything we did would look cheap or inappropriate. But two things turned me around.
| Jan 10, 2014
Special Report: K-12 school security in the wake of Sandy Hook
BD+C's exclusive five-part report on K-12 school security offers proven design advice, technology recommendations, and thoughtful commentary on how Building Teams can help school districts prevent, or at least mitigate, a Sandy Hook on their turf.
| Jan 10, 2014
Resiliency, material health among top AEC focuses for 2014: Perkins+Will survey
Architectural giantĀ Perkins+WillĀ recently surveyed its staff of 1,500 design pros to forcast hot trends in the AEC field for 2014. The resulting Design + Insights Survey reflects a global perspective.
| Jan 9, 2014
How security in schools applies to other building types
Many of the principles and concepts described in our Special Report on K-12 security also apply to other building types and markets.
| Jan 9, 2014
16 recommendations on security technology to take to your K-12 clients
From facial recognition cameras to IP-based door hardware, here are key technology-related considerations you should discuss with your school district clients.
