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
K-12 Schools | Nov 30, 2022
School districts are prioritizing federal funds for air filtration, HVAC upgrades
U.S. school districts are widely planning to use funds from last yearās American Rescue Plan (ARP) to upgrade or improve air filtration and heating/cooling systems, according to a report from the Center for Green Schools at the U.S. Green Building Council.Ā The report, āSchool Facilities Funding in the Pandemic,ā says air filtration and HVAC upgrades are the top facility improvement choice for the 5,004 school districts included in the analysis.
Architects | Nov 29, 2022
Three decades and counting, Tinkelman Architecture has helped reshape New Yorkās Hudson Valley
The full-service firm has designed more than 100 projects in this region, including several multifamily buildings currently in the works
Retail Centers | Nov 29, 2022
'Social' tenants play a vital role in the health of the retail center market
After a long Covid-induced period when the public avoided large gatherings, owners of malls and retail lifestyle centers are increasingly focused on attracting tenants that provide opportunities for socialization. Pent-up demand for experiences involving gatherings of people is fueling renovations and redesigns of large retail developments.
Giants 400 | Nov 28, 2022
Top 200 Office Sector Architecture and AE Firms for 2022
Gensler, Perkins and Will, Stantec, and HOK top the ranking of the nation's largest office sector architecture and architecture/engineering (AE) firms for 2022, as reported in Building Design+Construction's 2022 Giants 400 Report.Ā
Legislation | Nov 23, 2022
7 ways the Inflation Reduction Act will impact the building sector
HOKās Anica Landreneau and Stephanie Miller and Smart Surfaces Coalitionās Greg Kats reveal multiple ways the IRA will benefit the built environment.Ā
Multifamily Housing | Nov 22, 2022
10 compelling multifamily developments debut in 2022
A smart home tech-focused apartment complex in North Phoenix, Ariz., and a factory conversion to lofts in St. Louis highlight the notable multifamily developments to debut recently.
Digital Twin | Nov 21, 2022
An inside look at the airport industry's plan to develop a digital twin guidebook
ZoĆ« Fisher, AIA explores how design strategiesĀ are changing the way we deliver and design projects in the post-pandemic world.
Healthcare Facilities | Nov 17, 2022
Repetitive, hotel-like design gives wings to rehab hospital chainās rapid growth
The prototype design forĀ Everest Rehabilitation HospitalsĀ had to be universal enough so it could be replicated to accommodate Everestās expansion strategy.
Industrial Facilities | Nov 16, 2022
Industrial building sector construction, while healthy, might also be flattening
For all the hoopla about the ecommerce boom and ālast mileā order fulfillment driving demand for more warehouse and manufacturing space, construction of industrial buildings actually declined over the past five years, albeit marginally by 2.1% to $27.3 billion in 2022, according to estimates by IBIS World. Still, construction in this sector remains buzzy.
Wood | Nov 16, 2022
5 steps to using mass timber in multifamily housing
A design-assist approach can provide the most effective delivery method for multifamily housing projects using mass timber as the primary building element.