Remember that corner and perimeter columns do not have confinement on all four sides of the column. Also columns around openings will not have slab or beam confinement.
Puddling can be done with experienced contractors but inexpereinced contractors usually avoid puddling.
Often contractors will...
Could you explain further about why the confinement ties don't meet modern codes? Is it spacing? Or is it tie bar size? Or is it both?
Code confinement ties for columns tend to be a rather arbitrary conservative choice. ACI 318 notes that "Limited tests on full-size, axially-loaded, tied...
The difference in ultimate flexural strength calculations by changing from 5000 to 4000 psi is likely to be in the 1 to 2% range. The 5000 psi, as has been stated might be needed for durability and then a maximum water/cement ratio comes along with that. But for structural computations, we are...
ACI 318-11
11.9.9 Design of Shear reinforcement for walls
Ratio of horizontal shear reinforcement area to gross concrete area of vertical section shall not be less than 0.0025.
14.3 Minimum reinforcement
14.3.3 Minimum rato of horizontal reinforcement to gross area shall be:
(a) 0.0020 for...
