26.4.4 Documentation of Concrete Mixture Characteristics
(a) Documentation of concrete mixture characteristics shall be submitted for review by the licensed design professional before the mixture is used and before making changes to mixtures already in use. Evidence of the ability of the proposed mixture to comply with the concrete mixture requirements in the construction documents shall be included in the documentation. The evidence shall be based on field test records or laboratory trial batches. Field test records shall represent conditions similar to those anticipated during the proposed Work.
(b) If field or laboratory test data are not available, and fc' ≤ 5000 psi, concrete proportions shall be based on other experience or information, if approved by the licensed design professional. If fc' > 5000 psi, test data documenting the characteristics of the proposed mixtures are required.
(c) If data become available during construction that consistently exceed the strength-test acceptance criteria for standard-cured specimens, it shall be permitted to modify a mixture to reduce the average strength. Submit evidence acceptable to the licensed design professional to demonstrate that the modified mixture will comply with the concrete mixture requirements in the construction documents.