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
| May 16, 2013
Chicago unveils $1.1 billion plan for DePaul arena, Navy Pier upgrades
Hoping to send a loud message that Chicago is serious about luring tourism and entertainment spending, Mayor Rahm Emanuel has released details of two initiatives that have been developing for more than a year and that it says will mean $1.1 billion in investment in the McCormick Place and Navy Pier areas.
| May 16, 2013
Michael R. Bohn named Executive VP at Gilbane
Gilbane has promoted Michael R. Bohn to executive vice president. With over 28 years of service to the company and leadership roles on such high-profile projects as the University of Michigan Biomedical Science Building and the University of Chicago Medical Center, Bohn will now have responsibility for Gilbane’s New York and Midwest business units.
| May 15, 2013
Schneider Electric announces Global Xperience Efficiency Events for 2013
Schneider Electric’s Xperience Efficiency series will begin with events in the United States, China, Colombia, Brazil and Russia.
| May 15, 2013
Center for Green Schools, Architecture for Humanity release new tool for green schools
The 70-page guide demystifies the processes of identifying building improvement opportunities and finance and implementation strategies.
| May 14, 2013
Paints and coatings: The latest trends in sustainability
When it comes to durability, a 50-year building design ideally should include 50-year coatings. Many building products consume substantial amounts of energy, water, and petrochemicals during manufacture, but they can make up for it in the operations phase. The same should be expected from architectural coatings.
| May 14, 2013
Advanced turbines generate 6X more energy than conventional models
US-based wind energy company SheerWind just unveiled the INVELOX – a tunnel-based wind turbine that can produce up to 600% more power than traditional wind turbines.
| May 14, 2013
Raymond Clark joins HOK’s Chicago Practice as Management Principal
HOK announced today that Raymond Clark, AIA, LEED AP, has joined its leadership team in Chicago as senior vice president and management principal.
| May 14, 2013
Easy net-zero energy buildings [infographic]
"Be a Zero Hero" infographic educates building industry professionals on ultra energy-efficient structural insulated panel construction
| May 9, 2013
10 high-efficiency plumbing fixtures
From a "no sweat" toilet to a deep-well lavatory, here's a round up of the latest high-efficiency plumbing fixtures.