Tornado Shelter Missed Inspection 1

[NinerStruct]

We currently have a project under construction that has an ICC-500 shelter as part of the project. It's a precast concrete box with a hollow core floor bearing on interior 8" CMU shear walls with #5 @ 24" o.c. and a grouted bond beam at the top of the wall.

The issue is that the CMU walls were recently completed and, despite having a pre-construction meeting where the importance of inspection during masonry construction was stressed, neither the general contractor nor the mason notified the special inspection agent that they were needed on-site. The masonry should have been inspected continuously during reinforcing and grouting operations, instead, they haven't had even the bare minimum inspections required.

On top of that, the architect was on-site during one of the days of construction where the temperature was never over 40 degrees (was likely about 32 at the time of visit) and he did not see any evidence of heating the water or the sand. He didn't have any evidence of this, but this particular mason has had issues with not following cold-weather masonry construction requirements in the past.

I'm not advocating for them to tear them out and rebuild, but ultrasonic testing seems a bit lax for an ICC-500 shelter that didn't have any inspections. But the walls are not experiencing bending like an exterior wall and are mainly loaded axially and in-plane (which the o.o.p loading wasn't terrible, as we had many closely spaced walls) so maybe verifying the location of the reinforcing is acceptable?
If not, is there another acceptable type of testing/inspection that can be done after-the-fact that would be sufficient for an ICC-500 shelter?

 

[JAE]

1. Cut out sections for prism tests....contractor would have to replace. Probably do near the bottom of the wall.
2. Ensure that reinforced cells are fully grouted around rebar - not sure if ultrasonic can verify that vs. having the contractor knock open some face shells and allow some random cell visual inspection..then put back patching mortar or concrete.
3. Review your loads and if loads are small relative to your designed capacity (i.e. you were conservative in your design) then that gives you some rational leeway to accept limited special inspections....recalling that in past codes, masonry without special inspections had a penalty factor of 0.5 applied to the capacity (or rather - allowed an additional 2.0 factor on inspected masonry).

 

[JLNJ]

You might consider working with your local jurisdiction to see what they will accept.

We consulting engineers tend to make this painful for ourselves when it really should be painful for the contractor.

 

[Ron]

If you decide to do nondestructive testing, I would suggest ground penetrating radar instead of ultrasonic testing. With careful application and interpretation you can determine if rebar is encapsulated.