The choice between using a sheepsfoot roller, steel roller, or rubber tire roller depends on various factors, including the type of material being compacted, the desired compaction density, the project specifications, and site conditions. Here's a breakdown of when each type of roller is typically used:
Sheepsfoot Roller:
Type of Material: Sheepsfoot rollers are particularly effective for compacting cohesive soils such as clay or silt. The protruding knobs or feet on the roller penetrate and knead the soil, breaking up larger clumps and increasing density.
Moisture Sensitivity: Sheepsfoot rollers are often used when dealing with moisture-sensitive soils because they provide better compaction in wet or moist conditions compared to smooth drum rollers.
Specialized Applications: They are commonly used in areas where traditional smooth rollers might struggle, such as in the construction of dams, embankments, or other earthworks projects involving cohesive soils.
Steel Roller (Smooth Drum):
Versatility: Smooth drum steel rollers are versatile and can be used for compacting a wide range of materials, including granular soils, aggregates, asphalt, and base layers.
Surface Finish: They are ideal for achieving a smooth and uniform surface finish, making them suitable for road construction, pavement compaction, and finishing layers of asphalt.
High-Load Applications: Steel rollers are often used in high-load bearing applications where a dense and stable foundation is required, such as in highway construction or airport runways.
Rubber Tire (Pneumatic) Roller:
Surface Sensitive: Rubber tire rollers are well-suited for compacting non-cohesive materials like gravel, sand, or asphalt mixes. They exert pressure more evenly across the surface and are less likely to cause damage or deformation, making them suitable for finished surfaces.
Reduced Surface Friction: The rubber tires provide better traction and grip, allowing them to effectively compact asphalt mixes without causing marks or indentations.
Variable Weight Distribution: Some rubber tire rollers offer the advantage of adjustable ballast weight, allowing operators to vary the compaction effort based on the specific requirements of the material and project.
In summary, sheepsfoot rollers are preferred for compacting cohesive soils, steel rollers (smooth drum) are versatile and suitable for a wide range of materials, while rubber tire rollers are best for non-cohesive materials and finished surfaces. The selection should be based on the specific characteristics of the material being compacted and the desired outcome of the compaction process.