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
| Apr 16, 2012
Shawmut awarded Tag Heuer builds in Florida and Pennsylvania
Both projects are scheduled to be completed this spring.
| Apr 16, 2012
Batson-Cook breaks ground on senior living center in Brunswick, Ga.
Marks the third Benton House project constructed by Batson-Cook.
| Apr 16, 2012
Altoon + Porter Architects renamed Altoon Partners
The global practice, with offices in Los Angeles, Amsterdam, and Shanghai, specializes in retail, residential and mixed-use developments.
| Apr 16, 2012
Drake joins EYP as science and technology project executive
Drake’s more than 30 years of diversified design and project delivery experience spans a broad range of complex building types.
| Apr 16, 2012
$80 million in export financing for solar project in India
The project, “Rajasthan Sun Technique Energy Private Limited,” is a subsidiary of Reliance Power and is being co-financed by the Asian Development Bank and FMO, the Dutch development bank.
| Apr 13, 2012
Arcadis merges with Davis Langon & Seah
Merger will help company expand business in Asia.
| Apr 13, 2012
Goettsch Partners designs new music building for Northwestern
The showcase facility is the recital hall, an intimate, two-level space with undulating walls of wood that provide optimal acoustics and lead to the stage, as well as a 50-foot-high wall of cable-supported, double-skin glass
| Apr 13, 2012
Best Commercial Modular Buildings Recognized
Judges scored building entries on a number of criteria including architectural excellence, technical innovation, cost effectiveness, energy efficiency, and calendar days to complete, while marketing pieces were judged on strategy, implementation, and quantifiable results. Read More
| Apr 12, 2012
Solar PV carport, electrical charging stations unveiled in California
Project contractor Oltman Construction noted that the carport provides shaded area for 940 car stalls and generates 2 MW DC of electric power.
