How should admixtures be managed on a FDOT project?

• A. Ensure admixture type and dosage match the approved mix design, follow manufacturer instructions, and document usage.
• B. Use any available admixture.
• C. Ignore dosage.
• D. Document nothing.

Answer: (A)

Admixtures must be controlled to ensure the concrete performs as specified and there is a clear record of what was used. On an FDOT project, the admixture type and dosage should exactly match what’s approved in the mix design. Following the manufacturer’s instructions for handling, mixing order, and addition limits is essential for proper performance and compatibility with the cement and other materials. Recording details such as the product type, supplier, batch/lot, dosage, and when it was added creates a traceable QA record and helps with audits or any future investigations. Using an admixture outside the approved design or ignoring dosage would risk altering workability, set time, strength, air content, or durability, and failing to document usage breaks the QA chain.