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
Hotel Facilities | Jul 28, 2022
As travel returns, U.S. hotel construction pipeline growth follows
According to the recently released United States Construction Pipeline Trend Report from Lodging Econometrics (LE), the total U.S. construction pipeline stands at 5,220 projects/621,268 rooms at the close of 2022’s second quarter, up 9% Year-Over-Year (YOY) by projects and 4% YOY by rooms.
Codes and Standards | Jul 27, 2022
Biden administration proposes drastic flood insurance reform
The Biden administration’s proposed major overhaul to the National Flood Insurance Program, or NFIP, would drastically alter how Americans protect homes and businesses against flooding.
Concrete | Jul 26, 2022
Consortium to set standards and create markets for low-carbon concrete
A consortium of construction firms, property developers, and building engineers have pledged to drive down the carbon emissions of concrete.
Green | Jul 26, 2022
Climate tech startup BlocPower looks to electrify, decarbonize the nation's buildings
The New York-based climate technology company electrifies and decarbonizes buildings—more than 1,200 of them so far.
Education Facilities | Jul 26, 2022
Malibu High School gets a new building that balances environment with education
In Malibu, Calif., a city known for beaches, surf, and sun, HMC Architects wanted to give Malibu High School a new building that harmonizes environment and education.
| Jul 26, 2022
Better design with a “brain break”
During the design process, there aren’t necessarily opportunities to implement “brain breaks,” brief moments to take a purposeful pause from the task at hand and refocus before returning to work.
Building Team | Jul 25, 2022
First Ismaili Center in the U.S. combines Islamic design with Texas influences
Construction has begun on the first Ismaili Center in the U.S. in Houston.
Codes and Standards | Jul 22, 2022
Office developers aim for zero carbon without offsets
As companies reassess their office needs in the wake of the pandemic, a new arms race to deliver net zero carbon space without the need for offsets is taking place in London, according to a recent Bloomberg report.
Codes and Standards | Jul 22, 2022
Hurricane-resistant construction may be greatly undervalued
New research led by an MIT graduate student at the school’s Concrete Sustainability Hub suggests that the value of buildings constructed to resist wind damage in hurricanes may be significantly underestimated.
School Construction | Jul 22, 2022
School integrating conventional medicine with holistic principles blends building and landscape
Design of the new Alice L. Walton School of Medicine in Bentonville, Ark., aims to blend the building and landscape, creating connections with the surrounding woodlands and the Ozark Mountains.
