huangyhg

minimum (as) reinforcing steel in footing
in footings many engineers tend to ignore this minimum steel ratio bw x d x 200/fy . does aci or any thing relevant confirms this anywhere. thanks in advance.
you can only ignore it if 4/3 of the required steel is less than t&s steel. aci says that if your required stee; ratio is below the minimum steel ratio you can get around the 0.0033 minimum by increasing by 1/3.. if, however, you increase it by 1/3 and you are still below the minimum as for t&s you must use the minimum for t&s which is 0.0018bh.
in aci-318, section 10.5.1 gives that as the as,min for "flexural members". section 10.5.4, three paragraphs down, gives as,min for "structural slabs and footings of uniform thickness" as that required by 7.12.

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