A grader operator is performing a windrow mixing operation on a 1.5-metre wide windrow of granular material. To ensure efficient mixing, the mouldboard should be set so that:

Question: A grader operator is performing a windrow mixing operation on a 1.5-metre wide windrow of granular material. To ensure efficient mixing, the mouldboard should be set so that:

Answer options: ✅ The entire windrow is contained and rolled forward by the mouldboard, turning it over completely.

• Only the top half of the windrow is disturbed, allowing the bottom half to remain undisturbed.
• The mouldboard cuts deeply into the existing subgrade to bring new material to the surface.
• The mouldboard pushes the windrow directly off the side of the road.

Correct answer: The entire windrow is contained and rolled forward by the mouldboard, turning it over completely.

Explanation: For efficient windrow mixing, the mouldboard should be adjusted so that it encompasses the entire windrow. This allows the material to be thoroughly rolled and turned over by the blade as the grader moves forward, ensuring complete mixing of the granular material from top to bottom and side to side, which is essential for material uniformity.