Concrete Beam Shear 1

[haynewp]

If you were in a situation where a concrete beam's shear capacity was inadequate, is there literature on taking the longitudinal steel into account for the shear capacity?

 

[pankaj]

Normally the shear capacity is dependant on the longitudinal tension steel, the more the tension steel, the more is the shear capacity of the beam. And we have to provide shear stirrups for the balance of (shear force-shear capacity for provided tension steel).

But if the shear stress exceeds the maximum allowable shear stress, then there is no other option than to increase the concrete grade or the cross section of the beam.

Pankaj

 

[ronster]

There is nothing in the ACI as far as I am aware that a straight tension bar can be used to take additional shear forces. If you wish to bend the tension bar at the ends as appears to be common practice outside of the US then that is a different story. Are you dealing with an existing condition or designing a new beam?

 

[MLMoring]

Paragraph 11.3.2.1 of ACI 319-99 probably addresses you situation.

 

[haynewp]

thanks

 

[Qshake]

If I were in a position where the shear capacity were inadquate, I would at least look into the spatial constraints to see if external post-tensioning is feasible. Of course, this assumes it would be cheaper than building a new beam...don't really know what the situation is...many solutions exist.