ACI Concrete Field Testing Technician - Grade I Practice Exam

How many times must the rolling operation occur during the testing process?

1. 1 minimum

2. 2 minimum

3. 3 minimum

4. 4 minimum

The correct answer is: 2 minimum

The rolling operation is a critical part of ensuring the uniformity and proper consolidation of concrete within the mold during testing. This procedure typically requires a minimum of two passes with the rolling operation to adequately distribute the concrete and eliminate air pockets. The first pass serves to initially settle the concrete, helping to achieve a level and proper fill in the testing mold. The second pass provides further consolidation, enhancing the concrete's density and ensuring that it is properly prepared for accurate measurement of its properties. This two-pass method is recognized as a standard procedure in concrete testing to ensure reliable and consistent results, contributing to the overall integrity of the testing process.