When using a stand type mechanical shaker for sieving coarse aggregate, where is the sieve with the largest openings placed?

When using a stand type mechanical shaker for sieving coarse aggregate, placing the sieve with the largest openings by itself on the stand is a practice that effectively separates the material based on size. The principle behind this is that larger particles will not pass through the larger openings, allowing them to be retained on the surface of the sieve.

This setup allows for a clear distinction and prevents larger particles from being mixed in with smaller aggregates during the sieving process. It maximizes the efficiency of the sieving operation, ensuring that every particle is appropriately categorized based on size without risking clogging or unnecessary overlap of materials that could occur if the larger sieve were placed in a stack with other sieves.

In contrast, placing the largest sieve in other configurations, such as stacking it on top of smaller sieves or at the bottom, could lead to inefficiencies. If it were on top, fine particles could pass through and accumulate on it. Similarly, if it were placed in the middle or at the bottom of the stack, it could complicate the flow of materials, reducing the effectiveness of separation, as larger particles might not fall through as intended. This highlights the importance of strategic placement in sieve analysis for coarse aggregates.