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
Sponsored | | Jul 17, 2014
A major hop forward
The construction of efficient metal buildings has helped Perrault Farms expand its hops-harvesting business.
| Jul 17, 2014
22 land questions to decide if your build site works
When you’re ready to build, land needs a serious amount of attention. Since it can singlehandedly shift your building plans, land must be investigated, questioned, and eyed from every angle. SPONSORED CONTENT
| Jul 16, 2014
Mergers and acquisitions of AE firms on track for strong year in 2014
Through the first six months of 2014, Morrissey Goodale tracked 101 sales of U.S.-based architecture and engineering firms, roughly the same amount as during the first six months of 2013.
| Jul 16, 2014
Ware Malcomb announces New Jersey office expansion
Architecture and design firm also honored for commercial real estate projects in New Jersey.
| Jul 16, 2014
Learning design fundamentals in the digital age – How to balance learning and technology
My colleague and I were once asked an insightful question by a Civil Engineering Professor that sparked an interesting conversation. He’d been told about our software by some of his students who had used it during their summer internship. SPONSORED CONTENT
| Jul 16, 2014
Check out this tree-like skyscraper concept for vertical farming
Aprilli Design Studio has stepped forward with a new idea for a vertical farm, which is intended to resemble a giant tree. It uses lightweight decks as outdoor growing space, adding up to about 25 acres of space.
| Jul 16, 2014
User input on aquatics center keeps students in the swim [2014 Building Team Awards]
Collaborative spirit abounds in the expansion and renovation of a high school pool facility in suburban Chicago.
| Jul 16, 2014
Nonresidential construction starts up 34% in June
Construction starts for nonresidential work saw a surge in June, rising more than a third compared with the previous month, according to Reed Construction Data.
| Jul 16, 2014
ASHRAE, IAQA team up to improve resources on indoor air quality
Indoor Air Quality Association will become part of the ASHRAE organization while maintaining its own brand and board; HQ will relocate to Atlanta.
| Jul 15, 2014
Michael Graves talks with Washington Post about new design eye from life in a wheelchair
Celebrated American architect Michael Graves sits with the Washington Post to talk about how being on a wheelchair changed the way he focuses on design.
