Shear Ductility Requirments for Hollow Core Prestressed Slabs

[MSaffouri]

ACI requires the design moment strength to be 1.2 times the cracking moment strength (at least)
is there any requirement for shear capacity to be adequate in order to reach the 1.2*cracking moment?

 

[jayrod12]

I'm not familiar with ACI however it would only make sense that the shear capacity is higher than the moment capacity. I would prefer to see the hollowcore fail in bending so you could see the failure coming. Failure in shear is a sudden failure with little to no warning, especially in hollowcore where there are no shear stirrups.

 

[JAE]

Are you asking if it is possible to have a beam that has at least 1.2 times Mcr but does not have the necessary shear capacity, at its given span, to support a higher load to get to that capacity?

I think it might be possible but I'm pretty sure ACI doesn't have a similar 1.2 factor on shear other than requiring minimum shear capacity and/or stirrups.
For prestressed beams you also have compression on the section which adds to Vc.

 

[MSaffouri]

jayrod12: I agree with you & this is what triggers the question.

JAE: Thank you