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
Data Centers | Nov 13, 2023
Data center sector trends for 2023-2024
Demand for more data centers is soaring, but delivery can be stymied by supply delays, manpower shortages, and NIMBYism.
Education Facilities | Nov 9, 2023
Oakland schools’ central kitchen cooks up lessons along with 30,000 meals daily
CAW Architects recently completed a facility for the Oakland, Calif., school district that feeds students and teaches them how to grow, harvest, and cook produce grown onsite. The production kitchen at the Unified School District Central Kitchen, Instructional Farm, and Education Center, (“The Center”) prepares and distributes about 30,000 meals a day for district schools lacking their own kitchens.
Laboratories | Nov 8, 2023
Boston’s FORUM building to support cutting-edge life sciences research and development
Global real estate companies Lendlease and Ivanhoé Cambridge recently announced the topping-out of FORUM, a nine-story, 350,000-sf life science building in Boston. Located in Boston Landing, a 15-acre mixed-use community, the $545 million project will achieve operational net zero carbon upon completion in 2024.
Retail Centers | Nov 7, 2023
Omnichannel experiences, mixed-use development among top retail design trends for 2023-2024
Retailer survival continues to hinge on retail design trends like blending online and in-person shopping and mixing retail with other building types, such as offices and residential.
Giants 400 | Nov 6, 2023
Top 110 Cultural Facility Architecture Firms for 2023
Populous, Gensler, HGA, DLR Group, and Quinn Evans top BD+C's ranking of the nation's largest cultural facilities sector architecture and architecture engineering (AE) firms for 2023, as reported in the 2023 Giants 400 Report. Note: This ranking includes revenue from all cultural building sectors, including concert venues, art galleries, museums, performing arts centers, and public libraries.
Giants 400 | Nov 6, 2023
Top 170 Government Building Architecture Firms for 2023
Page Southerland Page, Gensler, Stantec, HOK, and Skidmore, Owings & Merrill top BD+C's ranking of the nation's largest government building sector architecture and architecture engineering (AE) firms for 2023, as reported in the 2023 Giants 400 Report. Note: This ranking includes revenue from all government building sectors, including federal, state, local, military, and Veterans Affairs (VA) buildings.
Designers | Nov 6, 2023
DLR Group opens office in Nashville, Tenn.
DLR Group is expanding its presence in the Southeast with the opening of an office in downtown Nashville, Tenn.—a collaborative effort led by DLR Group Principals Matthew Gulsvig, AIA, LEED AP, and Randall Coy.
Healthcare Facilities | Nov 3, 2023
The University of Chicago Medicine is building its city’s first freestanding cancer center with inpatient and outpatient services
The University of Chicago Medicine (UChicago Medicine) is building Chicago’s first freestanding cancer center with inpatient and outpatient services. Aiming to bridge longstanding health disparities on Chicago’s South Side, the $815 million project will consolidate care and about 200 team members currently spread across at least five buildings. The new facility, which broke ground in September, is expected to open to patients in spring 2027.
Office Buildings | Nov 2, 2023
Amazon’s second headquarters completes its first buildings: a pair of 22-story towers
Amazon has completed construction of the first two buildings of its second headquarters, located in Arlington, Va. The all-electric structures, featuring low carbon concrete and mass timber, help further the company’s commitment to achieving net zero carbon emissions by 2040 and 100% renewable energy consumption by 2030. Designed by ZGF Architects, the two 22-story buildings are on track to become the largest LEED v4 Platinum buildings in the U.S.
Sustainability | Nov 1, 2023
Researchers create building air leakage detection system using a camera in real time
Researchers at the U.S. Department of Energy’s Oak Ridge National Laboratory have developed a system that uses a camera to detect air leakage from buildings in real time.