Concrete Cover to Reinforcing Bars Less than ACI 318-14's Requirements

[Nor Cal SE]

I am plan reviewer and have a situation where an engineer has submitted a typ detail for a vertical conduit passing through a stud wall sill plate and concrete curb below at a typical exterior strip footing condition. As part of the detail, the designer shows the normal longitudinal reinforcing bar in the curb bending around the conduit stating 3/4" min concrete cover at this location. Clearly this does not meet ACI 318-14's minimum concrete cover for bars exposed to weather. However, should I consider this acceptable since the 3/4" cover occurs only at a very localized area, plus this is primarily temperature/shrinkage steel? Apart from the conduit condition, the details show the rebar running down the center of the curb as you'd expect; ample concrete cover. If I enforce 1-1/2" min concrete cover even at the conduit, I expect the designer will complain about how this will restrict potential conduit sizes.

 

[GC_Hopi]

Discontinue the bar at the conduit... curb may crack but if you offset the bar as described it may crack at least on one side anyways (dependent on the curb size and conduit size). The bar is not placed on the side adjacent to the building interior?

 

[Nor Cal SE]

Good thoughts. For clarity, the detail interrupts the typ longit bar both sides of the conduit and then laps 2 bars around the conduit, one on inside face and the other on outside face. These are #3 bars, both the typ longit bars and the short lapped bars that bend around the conduit.

 

[dik]

If the bar can be interrupted, is it better if continues, not withstanding the cover... assuming you don't have to paint it grey to look like concrete.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[phamENG]

If the conduit is that close to the face of the curb, I think trying to prevent cracking there is a fools errand anyway. Better to provide some sort of joint at that spot and just discontinue the reinforcing altogether.

My concern would be that you'll get a crack there regardless, but with the minimum cover violation water will have an easier time getting to the offset bar which can lead to rapid corrosion and spalling of the curb.