ACI Concrete Field Testing Technician - Grade I Practice Exam

How frequently must the rolling operation be performed during testing?

1. Once

2. Twice

3. Minimum of three times

4. Four times or more

The correct answer is: Minimum of three times

The rolling operation during testing must be performed a minimum of three times to ensure that the concrete is adequately worked and the consistency is properly assessed. This repeated rolling helps to provide a more reliable evaluation of the material's workability and uniformity. Performing the operation multiple times allows for a more thorough incorporation of air and reduces the risk of segregation, ensuring that the concrete mix is consistent throughout the sample. Testing protocols emphasize this frequency to enhance the accuracy of the results and validate the findings in real-world applications. Thus, adhering to this guideline is crucial for effective testing and reliable assessments in concrete field testing.