What actions are required if a concrete batch fails to meet specified strength or air/slump requirements?

• A. Stop placement as directed, segregate nonconforming concrete, notify the contractor and engineer, and document the nonconformance; arrange retesting or remediation.
• B. Ignore and continue placing.
• C. Increase curing temperature.
• D. Recycle the batch back into production without documentation.

Answer: (A)

When a concrete batch fails its strength or air/slump requirements, the first priority is to stop placing concrete and handle the nonconforming material properly. Stop placement as directed and keep the nonconforming batch separate from any conforming concrete to prevent contamination. Notify the contractor and the engineer so a decision can be made about disposition, and document the nonconformance so there’s a clear record of what happened. Then arrange retesting or remediation—the batch may be retested to verify if adjustments can bring it into spec, or it may need to be remediated or replaced according to project procedures.

This approach protects structural performance, ensures accountability, and provides traceability for QA/QC. Continuing to place nonconforming concrete would risk the integrity of the work; simply increasing curing temperature does not fix underlying strength or air/slump deficiencies; recycling the batch back into production without documentation bypasses required quality control and recordkeeping.