Your project specifications require granular bedding material for a storm sewer pipe with a minimum sieve analysis of 95% passing a 25 mm sieve and 5% passing a 0.075 mm sieve. What does this specification primarily ensure?

Question: Your project specifications require granular bedding material for a storm sewer pipe with a minimum sieve analysis of 95% passing a 25 mm sieve and 5% passing a 0.075 mm sieve. What does this specification primarily ensure?

Answer options:

• The material has a high plasticity index for optimal compaction. ✅ The material is predominantly coarse-grained with limited fines, providing good drainage and uniform support.
• The material is suitable for aesthetic landscaping after backfilling.
• The bedding material will act as a complete impermeable barrier.

Correct answer: The material is predominantly coarse-grained with limited fines, providing good drainage and uniform support.

Explanation: This sieve analysis specification ensures the bedding material is granular with a controlled range of particle sizes, primarily coarse. A large percentage passing 25 mm and a small percentage passing 0.075 mm (silt/clay) indicates good drainage properties and uniform support, which is critical for proper pipe bedding and preventing future settlement, adhering to engineering standards.