What is the opening size for a 1-1/2 inch box screen sieve?

The correct choice identifies that the opening size for a 1-1/2 inch box screen sieve is 1-1/2 inch square. This means that each side of the openings in the sieve measures 1-1/2 inches, allowing materials that are smaller than this size to pass through while retaining larger particles.

Understanding the concept of sieve openings is critical in construction and material testing, especially in ensuring that the right particle size is used for different applications within concrete and other materials. The square shape of the opening provides a uniform specification for testing and processing materials. This is relevant to various applications in civil engineering and construction.

In contrast, the other options provided do not appropriately reflect the defined size associated with a 1-1/2 inch box screen sieve. Round openings, or different square sizes, would not meet the designated criteria for classifying materials based on their particle sizes according to standard practices. Using the correct sieve size is essential for maintaining consistency and quality in construction materials.