huangyhg

aci 350 crack control provisions
we have been asked to accept or reject concrete walls in a wastewater treatment facility where the contractor has placed one of the reinforcing layers at mid-depth of the wall instead of 2" from the face of the wall as required. assuming that stresses are ok in some of the walls, is there a another basis for rejection such as servicability (crack control, etc.)? we don't have the newest aci 350 which corresponds to updated crack control provision aci 318 2005. in the new provision are you penalized for having excess cover? are there any other concerns?
i posted this on the concrete forum but apparently no one goes there.
article 14.3.4 of aci350 requires walls over 10 in thick to have two layers of reinforcement in each direction.
each layer must have 1/3 to 2/3 the total required reinforcement, and the maximum concrete cover at each face is limited to one third of the thickness of the wall from the surface.
why is the code exempting basement walls?
do exterior retaining walls require 2 layers also, or are they not covered in aci 318-02 because exterior retaining walls are not actually part of buildings?
if you check aci 224r-01, you can find the recommended cracking control procedures. this may help your decision.
pt999-
aci350 doesn't have the exemption. i believe aci318 exempts basement walls to allow for unreinforced walls designed according to chapter 22. aci350 doesn't allow for unreinforced concrete walls. i believe retaining walls over 10 inches thick are not exempted by aci318 article 14.3.4 and so require the 2 layers.

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