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
Architects | Apr 6, 2023
Design for belonging: An introduction to inclusive design
The foundation of modern, formalized inclusive design can be traced back to the Americans with Disabilities Act (ADA) in 1990. The movement has developed beyond the simple rules outlined by ADA regulations resulting in features like mothers’ rooms, prayer rooms, and inclusive restrooms.
Market Data | Apr 6, 2023
JLL’s 2023 Construction Outlook foresees growth tempered by cost increases
The easing of supply chain snags for some product categories, and the dispensing with global COVID measures, have returned the North American construction sector to a sense of normal. However, that return is proving to be complicated, with the construction industry remaining exceptionally busy at a time when labor and materials cost inflation continues to put pricing pressure on projects, leading to caution in anticipation of a possible downturn. That’s the prognosis of JLL’s just-released 2023 U.S. and Canada Construction Outlook.
Cladding and Facade Systems | Apr 5, 2023
Façade innovation: University of Stuttgart tests a ‘saturated building skin’ for lessening heat islands
HydroSKIN is a façade made with textiles that stores rainwater and uses it later to cool hot building exteriors. The façade innovation consists of an external, multilayered 3D textile that acts as a water collector and evaporator.
Market Data | Apr 4, 2023
Nonresidential construction spending up 0.4% in February 2023
National nonresidential construction spending increased 0.4% in February, according to an Associated Builders and Contractors analysis of data published by the U.S. Census Bureau. On a seasonally adjusted annualized basis, nonresidential spending totaled $982.2 billion for the month, up 16.8% from the previous year.
Sustainability | Apr 4, 2023
ASHRAE releases Building Performance Standards Guide
Building Performance Standards (BPS): A Technical Resource Guide was created to provide a technical basis for policymakers, building owners, practitioners and other stakeholders interested in developing and implementing a BPS policy. The publication is the first in a series of seven guidebooks by ASHRAE on building decarbonization.
Sustainability | Apr 4, 2023
NIBS report: Decarbonizing the U.S. building sector will require massive, coordinated effort
Decarbonizing the building sector will require a massive, strategic, and coordinated effort by the public and private sectors, according to a report by the National Institute of Building Sciences (NIBS).
Education Facilities | Apr 3, 2023
Oklahoma’s Francis Tuttle Technology Center opens academic center for affordable education and training
Oklahoma’s Francis Tuttle Technology Center, which provides career-specific training to adults and high school students, has completed its Francis Tuttle Danforth Campus—a two-story, 155,000-sf academic building. The project aims to fill the growing community’s rising demand for affordable education and training.
Sports and Recreational Facilities | Mar 30, 2023
New University of St. Thomas sports arena will support school's move to Division I athletics
The University of St. Thomas in Saint Paul, Minn., last year became the first Division III institution in the modern NCAA to transition directly to Division I. Plans for a new multipurpose sports arena on campus will support that move.
Warehouses | Mar 29, 2023
Construction completed on Canada’s first multi-story distribution center
Construction was recently completed on Canada’s first major multi-story industrial project, a distribution center in Burnaby, British Columbia. The project provides infrastructure for last-mile delivery in a world where consumers have come to expect next-day and same-day delivery, according to Ware Malcomb, the project's architect of record.
AEC Innovators | Mar 27, 2023
Leading architecture, engineering firm HED appoints new co-CEOs
As children of immigrant families, Van Herle and Suarez will bring a diverse perspective into a historically underrepresented industry and advance the firm’s mission of creating a positive impact for clients, communities, and the world.
