Which sieve size is used to indicate that fines will pass through?

• A. # 100
• B. # 200
• C. # 50
• D. # 300

Answer: (B)

The correct sieve size used to indicate that fines will pass through is the #200 sieve. This specific sieve size has openings of 0.075 mm (or 75 microns), which is designated for distinguishing finer particles in soil or aggregate samples. Materials that pass through this sieve are categorized as fines, which generally include silt and clay particles.

The #200 sieve is a critical reference point in laboratory testing because it helps in assessing the proportionality of fine particles present in a sample. This information is vital for understanding soil behavior, such as plasticity, permeability, and compaction characteristics, which significantly influence engineering applications and soil classifications.

Using a sieve of this size allows for consistent and standardized testing across various materials, ensuring that the results are meaningful for civil engineering practices. Proper identification of fines through this sieve enhances understanding of material suitability for construction, soil stabilization, and other engineering contexts.