NICET - Highway Construction Inspection Practice Exam

What is the primary use of a sheepsfoot roller in roadway construction?

1. Mixing asphalt

2. Compaction of soils in the subgrade

3. Grinding pavement surfaces

4. Preparing gravel bases

The correct answer is: Compaction of soils in the subgrade

The primary use of a sheepsfoot roller in roadway construction is for the compaction of soils in the subgrade. This type of roller features cylindrical feet arranged on its surface, which penetrate the soil and compact it effectively. The design allows it to apply both static and dynamic forces, ensuring that the soil is compacted thoroughly. This is critical for achieving a stable groundwork before laying asphalt or concrete, as it enhances the load-bearing capacity of the soil. In the context of roadway construction, proper soil compaction is essential because it helps prevent future settlement issues and maintains the integrity of the road surface. A sheepsfoot roller is particularly effective in cohesive soils, such as clay, where the foot design helps displace air pockets and achieve a dense, even compaction.