What defines overloading a sieve according to AASHTO?

• A. Using a sieve size #8 or more loaded with 2.5 times the sieve size
• B. Using a sieve size #4 or more loaded with 2.5 times the sieve size
• C. Using a sieve size #10 or more loaded with 3 times the sieve size
• D. Using a sieve size #16 or more loaded with double the sieve size

Answer: (B)

Overloading a sieve, according to AASHTO (American Association of State Highway and Transportation Officials), specifically refers to the situation where a sieve size #4 or larger is loaded with a sample mass that is 2.5 times the size of the sieve opening. This guideline is crucial as it ensures that the sieve can effectively separate the particles as intended during the particle size analysis process.

By adhering to this definition, testing accuracy is maintained, allowing for reliable classification of aggregate or soil samples in construction and engineering applications. The rationale behind the specified ratio ensures that the loading does not impede the screening process, which can result in inaccurate assessments of material quality and properties. In this context, using a larger sieve size incorrectly or with an inappropriate load could misrepresent the material's characteristics, leading to potential issues in design and construction.

The other options do not align with AASHTO's definition for overloading, as they refer to different sieve sizes or incorrect loading ratios that do not conform to established standards. This reinforces the importance of following the specified guidelines for accurate and reliable material testing.