Sieves larger than the 203.2 mm (8 in) diameter variety should be used for coarse aggregate testing to avoid the potential for overloading.

• A. False
• B. Not applicable
• C. True
• D. Cannot overload

Answer: (C)

When doing sieve analysis for coarse aggregates, it's essential to have enough screening area so the sample can be distributed and separated properly during shaking. Using a sieve with a larger diameter than 8 inches provides more surface area, allowing more material to be spread out and pass through the openings instead of piling up or bridging. This helps prevent overloading a single sieve, which would distort the gradation result and reduce accuracy. Standard practice for coarse aggregates emphasizes using larger-diameter sieves to maintain representative separation, especially with bigger maximum particle sizes. So, yes, larger-than-8-inch diameter sieves are used to avoid overloading and to obtain a reliable gradation.