The approved plans specify 3,000 psi concrete for the foundation, but the delivery ticket in the driver hand describes a 2,500 psi mix, and no revision has been submitted to the department. What is the correct action?
- ARelease the placement, because 2,500 psi is the code minimum for structural concrete and is therefore acceptable in a footing of any size.
- BRelease the placement if the driver adds water at the site to improve the workability of the mix just before it is discharged.
- CLet the pour proceed and then require core testing of the finished footing before any of the framing is allowed to start.
- Hold the placement, because the mix delivered has to match the strength shown on the approved plans unless a revision is approved.
Where to look it up
https://www.nrmca.org/association-resources/research-and-engineering/frequently-asked-questions-on-concrete-materials/
Why D is correct
The delivered mix is specified at 2,500 psi, below the 3,000 psi required by the supplied approved plans. Hold this placement while the discrepancy is resolved through the applicable approval process. Neither extra water nor a promise of later testing resolves that mismatch. This does not mean that all jobsite water adjustments are prohibited or that destructive testing is the only way to assess placed concrete.