What are composite joists?
|
Generally open web joists are the most economical framing system for poured in place concrete floors.
Although standard open web joists are economical, sometimes they are bouncy or deflect too much or are not strong enough for the job. These problems can be solved by making the joists composite with the poured in place concrete slab.
There is further improvement in the floor performance because the concrete haunch at the supporting beam encases the joist ends and locks the supporting beam into the composite system. The size of the beam can be reduced by the addition of standard shear studs which make it fully composite. The McManus composite joist is designed to make these advantages possible. |
|
|
|
We are different.Vibrations are deadened by the concrete haunch over supports. Since we do not project the top chord angles into the slab, as with other composite joist systems, you won’t experience slab cracking along the top of each joist.
During erection, the multispan decking is laid over the joist webs and can’t slip or slide off the supports. The decking can be “locked” in place with a few wedges until it is time to weld it down. Blow offs are prevented by the wedges. The decking can act as netting as the structure is erected for additional erection savings. |
Why should you use composite joists instead of conventional joists?
Better performance! When joined to the concrete slab, the composite joists are stiffer, stronger, and can span further than conventional joists.
Our composite joists have the added advantage of allowing the supporting steel beams to also become composite for a complete system. This is not possible with other composite joist designs.
We provide preliminary design information for architects, engineers, and builders and sell the basic floor system which includes joists and decking. Details and placement drawings are part of our responsibility.
Our composite joists have the added advantage of allowing the supporting steel beams to also become composite for a complete system. This is not possible with other composite joist designs.
We provide preliminary design information for architects, engineers, and builders and sell the basic floor system which includes joists and decking. Details and placement drawings are part of our responsibility.
Need further convincing?
Here are some other benefits:
- Reduced tonnage of steel
- Joists can be spaced to suit job requirements – from 2’-0” to 4’-0” c/c
- Slabs and joists are bonded to produce a superior diaphragm to resist wind and seismic forces
- Because we use long sheets of decking the joists and decking can be assembled on the ground in bay sizes for hoisting
- Two hour fire ratings with gypsum or acoustical ceilings
- The floor slab is reinforced with mesh for strength and shrinkage forces – slab cracking is controlled
- Greater saving in tonnage is possible with substitution of joist girders in place of steel beams
- Safer to erect than any other joist system – long decking sheets can not slide or lift off
- Full engineering backup
Tables, calculations, details and other information presented by MDGI pertaining to it’s Composite Joist System is for general guidance and estimating only and shall be reviewed and confirmed by a qualified engineer prior to its use in any structure.
