Composite Deck Superimposed Loads - Shored Construction

[XR250]

When using shored construction, do I need to add the weight of the concrete into the superimposed loads or is it already taken care of in the tables/online design tools?
I recall from about 20 years ago, the Vulcraft rep told me there is a large drop in the tables after you get past the limit of unshored construction to account for this.. I am not seeing that in the current tables though.

 

[jhnblgr]

you have to add it to the concentrated live load with concrete input.

 

[jhnblgr]

I stand corrected they included the DL +construction live load in their total calculations for uniform loading if you use their online tools
LL1= 20 psf this is for use with concrete
LL2= 50 psf this is for use without concrete

DL1= concrete + steel decking
DL2= steel decking

W1= LL1+DL
W2=LL2 + DL2

 

[IceNine]

The tables I have from Vulcraft specifically say superimposed live load.

Also, if you click on the strength tab on the online calculator, you will see they subtract out the dead load to arrive at the allowable superimposed load.

 

[XR250]

So the catalog says "superimposed live load" but the software says "superimposed load". They are off by about 100 psf for similar cases despite the concrete only weighing 63 PSF so maybe it is using a different deflection criteria. I cannot find that in the catalog.

 

[jhnblgr]

I was using the online software which shows the calculations

 

[jhnblgr]

I think the super imposed loads in the charts only applies to the finished product and has no relation to the shoring spans.

 

[XR250]

I think the super imposed loads in the charts only applies to the finished product and has no relation to the shoring spans.

Got it. Just checked and you are correct.
Thanks!

 

[XR250]

I think the super imposed loads in the charts only applies to the finished product and has no relation to the shoring spans.

So it is my recollection from doing these calcs years ago, that unshored construction has the pan bending stress baked in and that has to be subtracted from the stress in the pan due to the composite moment to determine the allowable moment. Shored construction won't have pan bending stress in there so the numbers should be different.

 

[LongTooth]

The tables are for superimposed load and they are considered to be live load. When calculating unshored spans, the bending stress in the extreme fiber controls. After construction, the entire section can be used to resist the tension. True on the superimposed load drop when shored (assumed 1- span condition in the tables). The AISI no longer requires this so it's no longer deducted. Not sure why. If you would feel more comfortable and want to adjust for shoring, subtract 5/8 of the slab weight from the superimposed load capacity.

 

[XR250]

Thanks. Good to know.