If the concrete contains aggregate larger than the maximum allowed for this test, the sample must be what?

When concrete contains aggregate larger than the maximum size permitted for a particular test, the sample must be wet sieved over a specified sieve size, in this case, a 1 ½ inch sieve. This process ensures that any oversized particles are effectively removed while retaining the necessary material that adheres to the maximum aggregate size limits for the test.

Wet sieving prevents the aggregation of fine particles that might occur in a dry sieve procedure and helps maintain accuracy in the test results by ensuring the consistency of the sample being tested. By using water during the sieving process, it minimizes dust and helps in separating finer materials from larger aggregates, providing a more accurate representation of the maximum aggregate size allowed in concrete mix design.