Soil and Asphalt Compactors Information
Soil and asphalt compactors compress soil, asphalt, crushed aggregates or landfill trash. These machines range from small walk-behind or pull-utility rollers, rammer compactors, plate compactors, and machine mounted hydraulic compactors to large, driven, roller vehicles. They are also known as road rollers or steamrollers.
Hydraulic compactors are mounted on hydraulically-powered equipment such as excavators and backhoes. Commonly referred to as vibratory compactors, these machines are used for soil and material compaction in trenching, street repair, and site preparation. T
hey deliver high impulse energy to compact the aggregate by use of an oscillating hydraulic motor. Rubber isolators are used to sequester the hydraulic motor and base compactor plate from the mounting bracket to maximize the energy transferred through the compactor plate.
Rammer/tamping compactors and vibratory plate compactors are hand-controlled compactors used for smaller projects or where space is limited. They work by aggressively applying consecutive impacts to the surface of the soil in order to level it. Rammers and plate compactors are designed to compact loose soils and gravel to prevent settling and to provide a firm, solid base for the placement of footings, concrete slabs, foundations, and pipe works. These compactors can be powered by electric or gas engines and are available with a variety of vibratory soil plates sizes.
Roller compactors are large, driven vehicles available in various configurations for compacting soil and asphalt on large projects. Some large roller compactors are specifically designed for compacting trash at landfills.
Grid rollers have a cylindrical, heavy steel
surface composed of an array bars forming a grid with square holes. While relatively lightweight, the compaction energy can be increased by adding mass, such as concrete blocks. Grid rollers provide high contact pressure but little kneading action and are suitable for compacting coarse soils.
A smooth-wheeled roller is a large, driven vehicle that consists of one large steel drum in front and two steel drums on the rear; those with a single drum on the front and rear are called a tandem roller. Smooth-wheeled rollers are available with a vibrating drum that allow for greater compaction depth. These are best suited for rolling weaker aggregates, proof rolling subgrades, and compacting asphalt.
Pneumatic tire rollers are large, driven vehicles that have rubber tires on both axles. The tires are staggered for compacting soil layers with uniform pressure throughout the width of the roller. These rollers compact both fine-grained and non-cohesive soils. Pneumatic tire rollers are also used in pavement subgrade work.
Tamping rollers and sheep foot rollers have many round or rectangular shaped knobs on each wheel or drum. Such rollers may be dedicated compacting vehicles or pull-behind attachments. The primary difference between the two machines is the configuration of the knobs on each roller. Sheep foot roller knobs lift the subsurface material to the top by penetrating through the top surface to lift a lower level to the soil surface, leaving a fluffed effect. Tamping rollers have knobs that provide a concentrated compressive load to essentially seal the surface as it compacts and travels over it. Tamper rollers operate at higher speeds, and because they are used for spreading and compacting they are often equipped with a spreading blade.