New Millennium Building Systems

Flex-Joist™
Gravity Overload Safety System™

Steel Joist Institute, ANSI, Steel Deck Institute Steel Joist Institute ANSI Steel Deck Institute

Flex Joist Overload Safety System

 

Gravity overload safety

The Flex-Joist™ Gravity Overload Safety System™ offers additional safety features to building owners and managers who are concerned about potential overload conditions and the related risks of damage or injury. The system introduces several new advantages, as follows:

 

  • Engineered overload safety for floors and roofs
  • Steel joist structure is designed to flex under extreme static gravity overloading
  • Time delay for possible evacuation and injury prevention
  • Provides for possible shoring, removal and collapse prevention

Downward force on structural components

 

  • Engineered overload yielding
  • Timeframe for emergency management
  • Enhances building safety

 

 

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Download the Brochure (pdf)
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How the system works

 

Flex-Joist with strain gauge

1. Early detection: Within a Flex-Joist Gravity Overload Safety System, each steel joist is engineered to flex in the event of an overload to establish the new element of time-delay before the collapse of a steel joist roof or floor structure. Strain gauges throughout the system measure ductile tensile yielding within the structure, detecting a problem early, well in advance of a collapse.

Structural overload alarm notification

2. Notification: A steel joist overload condition can alarm locally and remotely. This simple safety solution can function as a stand-alone management package or be integrated into an existing building alarm system.

Structural overload information system

3. Overload location and status: Informed of the location of an overload, management can also “see” the estimated status of the overload. The system provides a measure of available response time, allowing for decisions as to evacuation, roof shoring and load removal.

Flex-Joist engineered yield time
Compared to traditional joist systems, the Flex-Joist is engineered to collapse after a significantly longer yield time, in the event of a static gravity overload. This is because Flex-Joist design promotes tensile yielding.

Flex-Joist™ is different by design

Flex-Joists are designed for superior performance under unanticipated gravity loads in excess of engineered capacity. While not intended to outperform traditional joist systems under lateral or uplift load events such as a tornado, hurricane or seismic event, Flex-Joist design provides better protection in the more common overload scenarios such as rain, snow and floor live loads.

 

Flex-Joists differ in two fundamental ways:

1) Component relative strength ratios

2) Adjacent joist load sharing

 

In a Flex-Joist system, each joist component is designed with relative strength ratios, such that the joist can, in the event of extreme overload, experience ductile tensile yielding in the bottom chord and end webs.

 

Find out more…
Download the Brochure (pdf)
Contact us for more information

 

Disclaimer: No joist will withstand sudden and catastrophic impact forces that exceed system capability. Flex-Joist design offers probability of high ductility and time delay under static gravity overload conditions.

Steel Dynamics, Inc

New Millennium Building Systems is a wholly owned subsidiary of Steel Dynamics Inc.