Air meter bowls used for this test must conform to which standards?

The correct choice indicates that air meter bowls used for testing must conform to ASTM C231 and ASTM C29/C29M standards. ASTM C231 specifically addresses the method for determining the air content of freshly mixed concrete using the pressure method, which is crucial for ensuring that the concrete mix contains the appropriate amount of air for performance and durability. ASTM C29/C29M outlines the sampling and testing of aggregates, including the test method for determining the bulk density of aggregates.

These standards are essential because they ensure that the equipment used in the testing process is compatible with the required testing methods, providing accurate results that are critical for quality control in concrete production. By adhering to these standards, practitioners can ensure that they employ reliable techniques for assessing the properties of concrete mixes, which directly impacts their structural integrity and long-term performance.

The other options, while they may mention relevant ASTM standards, do not include the correct pairing necessary to properly meet the testing requirements for air meter bowls. Understanding the specific standards required supports maintaining industry best practices and adherence to guidelines that ensure consistent and reliable concrete quality assessments.