If the mass passing through any sieve after one minute exceeds 0.5% of the original mass, the sieve analysis is considered inadequate.

• A. True
• B. False
• C. Not specified
• D. Only for coarse aggregates

Answer: (A)

The test centers on an adequacy check for sieve analysis. When you shake the sample on a stack of sieves, you expect small amounts to begin passing through quickly, but there’s a strict limit: if more than 0.5% of the original mass passes a given sieve within the first minute, the analysis is deemed inadequate. This threshold helps ensure the separation is being performed properly and that the resulting gradation data are reliable. Exceeding it can indicate problems like worn or damaged sieves, improper shaking, or an overly fine sample, all of which would bias the results. For example, with a 1000 g sample, more than 5 g passing a sieve in the first minute would trigger the inadequacy flag. This rule applies to all sieves in the stack, not just coarse ones.