What is the term for particles with a diameter larger than 75 mm?

The term for particles with a diameter larger than 75 mm is indeed "cobbles." In the context of soil and aggregate classification, particle size is used to categorize materials into specific groups.

Cobbles are defined as coarse aggregates that fall within a size range that exceeds 75 mm in diameter. This classification is important for various engineering applications, as it affects how materials are used in construction, drainage, and other civil engineering projects. Cobbles can provide excellent drainage when used in aggregate bases or sub-bases and are often used in erosion control and landscape design due to their size and stability.

In contrast, gravel, sand, and fines refer to smaller particle sizes, which would not fit the definition of particles larger than 75 mm. Gravel generally consists of particles that range in size from 4.76 mm to 75 mm, while sand has particles smaller than 4.76 mm down to a minimum size of 0.075 mm. Fines are composed of even smaller particles, generally smaller than 0.075 mm. Understanding these distinctions is critical for effective material selection and application within civil engineering practices.