ACI Concrete Field Testing Technician - Grade I 2025 – 400 Free Practice Questions to Pass the Exam

When portions of undisturbed concrete are found in the air meter at the conclusion of the test, it indicates that the sample did not undergo the proper mixing and agitation necessary for accurate air content measurement. The air meter relies on a homogeneously mixed sample to provide reliable readings, ensuring that all air voids can effectively interact with the testing mechanism.

The presence of undisturbed concrete suggests that the sample may have segregated or that the mixing process was insufficient, leading to an inaccurate and misleading measurement of air content. Therefore, this scenario qualifies the results as invalid. An invalid test means that the data cannot be used for quality control or assurance, and it emphasizes the need for proper sampling and mixing techniques to achieve reliable results in future tests.

In this case, it is crucial to restart the testing process with a properly prepared sample to obtain an accurate air content measurement. While options indicating the test might be valid, incomplete or repeatable might seem plausible, they do not account for the significant implication of the undisturbed concrete presence, which undermines the reliability of the test results entirely.