Shear Strength Provided by Web Reinforcement, old (LFD) AASHTO vs LRFD AASHTO

[MoShal]

In old AASHTO (LFD) the maximum steel contribution in shear is limited to Vs_max = 8 sqrt_f'c b d. In LRFD AASHTO, there are 2 equations for the shear capacity, the lesser one will govern. So I tried to compare between them and I got about 2.47 times difference. My current design using the LFD code for the bridge girder is governed by this limitation. Please check the attached file for the comparison. Did they increased the steel contrition limitation in the LRFD AAASHTO by 250%?

 

[ernestog84]

I've never used LFD, but try comparing the Load from LFD vs LRFD and see if you get a similar difference.