For starters this is a very sticky situation, this could end badly since the concrete itself is being used as a structural member. That is pretty much fragile since it will not be at full strength. Therefore this may be a life threatening matter, that being said it makes me wonder:
If the owner and superintendent are aware of the dangers of cheating a structural member?
Why did the architect have to find out the way he/she did?
Since there was an agreement, Why didn’t the client consult with the architect? Therefore, there is a violation in the contract.
Therefore the architect will have to ensure that the concrete is removed and replaced with the original concrete, but the relationship with client/superintendent/architect will be rocky.
Steps for the Architects:
The architect can not withhold payment since the owner is aware, even if they tried cheating the concrete design. Due to 4.2.2 . However, the Architect will not be required to make exhaustive or continuous on-site inspections to check the quality or quantity of the Work. The Architect will neither have control over or charge of, nor be responsible for, the construction means, methods, techniques, sequences or procedures, or for the safety precautions and programs in connection with the Work, since these are solely the Contractor’s rights and responsibilities under the Contract Documents, except as provided in Subsection 3.3.1.
Therefore the Architect will have to follow:
4.2.5 Based on the Architect’s evaluations of the Contractor’s Applications for Payment, the Architect will review and certify the amounts due the Contractor and will issue Certificates for Payment in such amounts.
4.2.8 The Architect will prepare Change Orders and Construction Change Directives, and may authorize minor changes in the Work as provided in Section 7.4. The Architect will investigate and make determinations and recommendations regarding concealed and unknown conditions as provided in Section 3.7.4
9.8.5 The Certificate of Substantial Completion shall be submitted to the Owner and Contractor for their written acceptance of responsibilities assigned to them in such Certificate. Upon such acceptance and consent of surety, if any, the Owner shall make payment of retainage applying to such Work or designated portion thereof. Such payment shall be adjusted for Work that is incomplete or not in accordance with the requirements of the Contract Documents. For going against the local building code and specifications, which could have ended poorly.