ACI Certification Practice Exam

During slump testing, if concrete shears off from one side of the sample, what action should the technician take?

1. Ignore the results and continue

2. Report the results as is

3. Prepare a new sample

4. Wait for further instructions

The correct answer is: Prepare a new sample

In slump testing, the main goal is to assess the workability or consistency of freshly mixed concrete. If the concrete shears off from one side of the sample, this indicates that the sample may not have been compacted properly or that the consistency is too low, leading to inaccurate results. For the test to be valid and reflect the true properties of the concrete mix being tested, it’s essential that the sample is properly formed and stable during testing. Preparing a new sample ensures that the results will be reliable and can accurately inform decisions regarding the mix's workability. A compromised sample can lead to misleading interpretations of the concrete's performance, which can have significant implications for construction quality and safety. Ignoring the results, reporting them as is, or waiting for further instructions would not rectify the issue with the sample. Each of these options risks using unreliable data, which could affect the quality of the concrete used in construction. Therefore, the appropriate course of action is to prepare a new sample for testing.