What action should be taken if several gradation tests indicate that aggregates are falling outside control limits?

When several gradation tests indicate that aggregates are falling outside control limits, the appropriate action is to have the contractor's certified concrete technician determine and correct the issue. This response emphasizes the importance of maintaining quality control in the concrete production process.

A certified concrete technician possesses the knowledge and expertise to analyze the situation, identify the underlying causes of the gradation discrepancies, and implement corrective measures to bring the aggregate gradation back within acceptable limits. This proactive step is critical because aggregates that do not meet specified gradation criteria can adversely affect the performance, durability, and overall quality of the concrete.

It is crucial to address the issue through proper investigation and resolution rather than accepting the material as acceptable, discarding the stockpile, or ignoring the test results, as these actions could lead to poor-quality concrete and potential failures in the structure being constructed.