# PCI Design Handbook - Headed Stud

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### #1 Mike1144

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Posted 30 April 2007 - 02:59 PM

I can't quite figure out the units for the breakout strength coefficient in section 6.5.4.1 of the PCI Design Handbook, 6th ed. I'm guessing it should come out to lbs/in^2. Is there a specific unit associated with the 3.33 value?

I also can't quite seem to find what the lambda factor is. Is it 1.3 for lightweight, just like in rebar development? Or is it the 0.85 for lightweight, and 0.75 for sand lightweight? 0.85 and 0.75 make more sense since they would lower the overall capacity in this case.

### #2 kevo_55

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Posted 30 April 2007 - 05:39 PM

Mike,

I don't have it infront of me, but the PCI 6th edition is >90% like the appendix D of ACI 318-02.

You might want to double check some things in there.

I hope this helps!!

### #3 Mike1144

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Posted 30 April 2007 - 07:04 PM

Mike,

I don't have it infront of me, but the PCI 6th edition is >90% like the appendix D of ACI 318-02.

You might want to double check some things in there.

I hope this helps!!

ACI is even worse with units. I've looked through the ACI318 as well. The PCI book even has references to the ACI318 AppD. So if raise a length to the 5/3 power, you still get inches?

I've kinda got the units for the 3.33*lambda*Sqrt(f`c/hef) to work out. There is still no clear definition of the lambda value that I can find. PCI even says its equations is equivalent to some values in the ACI. But those values make no mention of the weight of the aggregate.

I'm not trying to solve any real world problems, I just want to understand this stuff better.

### #4 teda

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Posted 01 May 2007 - 03:05 PM

I can't quite figure out the units for the breakout strength coefficient in section 6.5.4.1 of the PCI Design Handbook, 6th ed. I'm guessing it should come out to lbs/in^2. Is there a specific unit associated with the 3.33 value?

I also can't quite seem to find what the lambda factor is. Is it 1.3 for lightweight, just like in rebar development? Or is it the 0.85 for lightweight, and 0.75 for sand lightweight? 0.85 and 0.75 make more sense since they would lower the overall capacity in this case.

It is psi.

As far as I know, light weight concrete was not covered in ACI App.D.

### #5 kevo_55

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Posted 01 May 2007 - 04:51 PM

teda,

LWC is in appx D. Please see D3.4.

Getting back on topic, ACI/PCI uses data to come up with equations to fit. For whatever reason, they choose some pretty weird curves to fit this data. What I typically so is to look in the nomenclature to see the units you put into each equation and forget about cancelling everything out.

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