An operator is windrow mixing granular material for a segment of road 500 metres long and needs to ensure thorough mixing. How many passes are typically recommended as a minimum for effective windrow mixing, assuming an average-sized windrow and standard material?

Question: An operator is windrow mixing granular material for a segment of road 500 metres long and needs to ensure thorough mixing. How many passes are typically recommended as a minimum for effective windrow mixing, assuming an average-sized windrow and standard material?

Answer options:

• 2-3 passes ✅ 6-8 passes
• 10-12 passes
• 1 pass

Correct answer: 6-8 passes

Explanation: For effective windrow mixing to achieve uniform material distribution and moisture content, typically 6-8 passes are recommended. This allows the material to be thoroughly blended and turned over multiple times, preventing segregation and ensuring a consistent mix throughout the entire windrow, as taught in HEO training.