ACI Concrete Field Testing Technician - Grade I Practice Exam

According to ASTM Standards, how should the concrete sample be obtained for the test method?

1. C150

2. C172

3. A123

4. C94

The correct answer is: C172

The correct answer is based on ASTM C172, which specifically outlines the procedures for sampling fresh concrete. This standard provides essential guidelines for obtaining representative samples from a batch before various tests are conducted. It emphasizes the importance of collecting samples at the point of discharge from the truck or mixer, ensuring that the sample represents the entire load and the characteristics of the concrete being tested. ASTM C172 details the specific techniques for obtaining and handling the sample, including the minimum volume needed for testing and the need to maintain the integrity of the sample during transportation to the testing location. This is critical because any deviation from the specified sampling procedures could lead to inaccurate test results, impacting quality control and assurance. The other standards listed do not relate specifically to sampling procedures for fresh concrete; for example, ASTM C150 deals with the specifications for Portland cement, ASTM A123 covers the specifications for zinc (hot-dip galvanized) coatings, and ASTM C94 outlines the specifications for ready-mixed concrete. Therefore, these options are not suitable for addressing how a concrete sample should be obtained for testing purposes.