Can I design the shear reinforcement spacing to exceed the maximum spacing?

[AzzA16]

Hello Everyone

I have a beam with dimensions of 200mm x 300mm, with a maximum spacing of 60mm. The nominal shear value with a spacing of 100mm is still more than enough to resist the occurring Vu. Can I use that 100mm spacing?

 

[GeorgeTheCivilEngineer]

What clause is driving a max spacing of 60mm?

 

[ALK2415]

Only in spiral reinforcement you will find minimum spacing of 3" [75 mm]

 

[milkshakelake]

Is 200mm your depth, or is it 300mm?

I'm not sure which code you're using. In ACI 318, stirrup spacing is generally (effective depth)/2 except when the amount of reinforcement required is very high compared to the concrete shear strength, in which case the spacing becomes (effective depth)/4. If your code has something like that and you have triggered that provision, then you do need to use the smaller 60mm spacing.

The code itself will ultimately tell you what you can and can't do. If your depth is 300mm and your spacing is 100mm, that seems okay to me, but you'd have to explain why the code is saying you need 60mm. And you can't violate it if it really says that you need 60mm.