What method is used to determine the distribution of particle sizes larger than 75um?

The correct approach to determine the distribution of particle sizes larger than 75 micrometers involves the method known as sieving. This process utilizes a series of screens or sieves, each with different mesh sizes, to separate particles based on their size. The particles that pass through the larger openings are retained in the larger-sized sieve, while smaller particles fall through, allowing for a thorough analysis of size distribution.

Sieving is particularly effective for granular materials, such as aggregates, where proper size distribution can significantly affect the material's properties, such as compaction and stability. Using this method, technicians can effectively quantify the proportion of particles in various size ranges, facilitating better material selection and quality control in construction and engineering projects.