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Equipment Specifications - RitchieSpecs
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1990 Mueller TS22 Compactor
Compactors are machines frequently used to compact materials such as soil in order to increase its density for construction.[1] In addition, compactors are utilized in landfill tasks.[2] Common varieties are plate tampers (also known as rammers),[3] vibratory plates, compactors (also known as tamping foot rollers),[4] and vibratory padfoot compactors. These categories are further divided below.

Contents

[edit] History

Early compaction was accomplished using rollers that were drawn by horses. By the mid-19th century, horse-drawn rollers were displaced by self-propelled steamrollers, from which modern compactors are derived. See rollers.

[edit] Features/How it Works/Types

Each type of compactor is suitable for a particular application; small-scale tasks can be completed using walk behind machines, whereas ride-on compactors are used in larger jobs. Four types of compaction can be carried out, depending on the machine used. These are vibration, impact, kneading, and pressure. Compactors using vibration have a tendency to dry out soil, which can be advantageous when soil is excessively moist.[5] Compactors are walk behind, tow behind, or ride-on.

[edit] Walk Behind Compactors

Walk behind compactors are used for smaller applications and include plate tampers, vibratory plates, and vibratory walk behind padfoot compactors.

[edit] Plate Tampers

Plate tampers are walk behind compactors used to compact gravel, sand or soil on a small scale using impact, vibration, and kneading. These machines are used on cohesive and semi-cohesive soils, as they are capable of applying a high impact force with high amplitude. This force is delivered at a rate of approximately 500 to 750 blows per minute.[6] Plate tampers are outfitted with a small gasoline or diesel engine that provides power to a large piston fitted with two sets of springs. In operation, these compactors must be tilted forward to enable them to move forward as they jump.

[edit] Vibratory Plates

These low amplitude walk behind compactors are effective in compacting granular soils and asphalt through vibratory action of a base plate; the heavier the plate, the greater the compaction force. They are comprised of one or two eccentric weights that are driven by gasoline or diesel engines. The vibrations resulting from this action cause the compactor to move forward. When these compactors are used for asphalt applications, they include a water tank and sprinkler to prevent asphalt from adhering to their base plate. Vibratory plates are also available in reversible models, fitted with two eccentric weights to make a smooth transition between forward and backward motions, useful for compacting semi-cohesive soils. In contrast to standard vibratory plates, this model will engage in spot compaction if its forward motion is stopped.

1999 Rex 335C Compactor
[edit] Vibratory Walk Behind Padfoot Compactors

Vibratory walk behind padfoot compactors are also known as trench rollers,[7] as they are effectively used in trenches and excavation jobs. They are equally useful in small scale or narrow tasks such as sidewalks. They consist of padded drums that provide compaction with a kneading action; additional compaction is carried with a high impact force that is useful on cohesive soils. These highly productive machines, using diesel engines, are steered and operated hydraulically or hydrostatically, and are either skid-steer, or have articulated steering. Trench rollers can be operated manually or by remote control.

[edit] Tow Behind Compactors

These compactors are most often used to compact soil, gravel, sand, and asphalt. They are normally used in roadbuilding jobs, but may be applied in other tasks as well. These fairly simple implements are available with either single or tandem drums, the widths of which are variable. The foot shapes on these drums are often “sheepsfoot”, a style that has a tendency to tear and displace land;[8] sheepsfoot rollers have become basically obsolete, in favor of padfoot drums. Tow behind grid or mesh rollers, utilizing pressure and impact compaction, are also available. These compactors, capable of high speeds without scattering earth, are effective on cohesive soil.

[edit] Ride-on Compactors

Ride-on compactors are generally used for larger applications. The ride-on category includes vibratory padfoot compactors and tamping foot rollers, also known as compactors.

[edit] Vibratory Padfoot Compactors

Vibratory padfoot compactors are ride-on models, consisting of drums outfitted with segmented pads, used to compact soil and other materials using vibration. These self-propelled, diesel-powered compactors are comprised of a single vibrating padfoot drum, and pneumatic drive wheels. These compactors may include a front attachment such as a dozer, a cab, and rear attachment, and hydrostatic drive. Ride-on, manually or remote control operated versions of walk behind padfoot compactors (trench rollers) are available for tasks that require high productivity in tight or confined areas.[9]

[edit] Compactors (Tamping Foot Rollers)

Large ride-on machines with tandem rollers are commonly referred to as tamping foot rollers, or simply as compactors. They achieve compaction through pressure and kneading, in addition to impact force. Additionally, vibratory compaction is achieved as high-speed machines impact the soil at a frequency close to vibration.[10] These machines normally have segmented static padfoot rollers, ranging in diameter from 30 to 110 inches (76 to 279 cm).[11] Sheepsfoot rollers, comprising protruding feet instead of pads, are available on these machines but are not as widely used. These machines use their pads or feet to achieve effective compaction in both construction and landfill applications. Powered by a diesel engine, these machines often include a blade, a cab, and a rear attachment. Additionally, they may include hydrostatic drive.

[edit] Common Manufacturers

[edit] Additional Photos

BOMAG K351 Landfill Compactor
2005 Caterpillar 815F Compactor

[edit] References

  1. Soil Compaction. Concrete-Catalog. 2008-09-23.
  2. Ritchie Bros. Auctioneers. Equipment Valuation Assistant. Ritchie Bros. Auctioneers Incorporated: 2004.
  3. http://www.concrete-catalog.com/soil_compaction.html
  4. Nunnally, S.W. Managing Construction Equipment. Prentice-Hall, Inc: 1977.
  5. Nunnally, S.W. Managing Construction Equipment. Prentice-Hall, Inc: 1977.
  6. Soil Compaction. Concrete-Catalog. 2008-09-23.
  7. Soil Compaction. Concrete-Catalog. 2008-09-23.
  8. Nunnally, S.W. Managing Construction Equipment. Prentice-Hall, Inc: 1977.
  9. Soil Compaction. Concrete-Catalog. 2008-09-23.
  10. Nunnally, S.W. Managing Construction Equipment. Prentice-Hall, Inc: 1977.
  11. Soil Compaction. Concrete-Catalog. 2008-09-23.