Guide to Light Compactors
Soil compaction is a critical job in construction, allowing contractors to build structures that are stable, well-supported and level. Highly compacted earth eliminates pore spaces between soil particles, reducing the risk of infiltrating moisture, pests and other risks to ground stability. Since soil naturally shrinks and expands throughout the seasons, it can cause buildings to shift in response. Compacting soil allows structures to remain stable and increases their load-bearing capacity, making them more functional and long-lasting.
This guide to light compactors will cover the types of compaction forces that different equipment types use. We'll also provide guidance on how to pick the right type of light compactor for your application, including the different types of soil each compactor is suitable for.
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What Are Light Compactors?
Light compactors are specialty compaction tools used in construction for smaller compaction jobs. Their smaller size makes them easy to maneuver and prevents over-compaction that you might get with heavier-duty machines. Light compactors are essential tools for narrow or confined spaces, giving you the workability you need. Light compactors are less expensive to operate, undergo lower rates of wear and tear and are easier to replace, service and repair.
To achieve tight soil compaction, contractors need the right mechanical tools and techniques to compress the earth to a desirable level. It's also critical not to overdo it, as over-compaction can lead to premature fracturing, resulting in destabilization of the structure. Therefore, it's essential to choose compaction tools that are rated appropriately in force and size and offer the right scope for the given project, including the soil type.
Learn more about choosing the right compaction equipment for your project.
Types of Compaction Forces
Soil compaction can be achieved using two types of downward force from the machine into the surface:
Static Force
With static force, you apply the machine's weight alone down into the soil. You can either knead the equipment or put added pressure on it, such as by adding your own bodyweight, to achieve static compaction.
To achieve the right compaction level, you can either add or remove weight from the machine, meaning you are limited with much compaction you can achieve using a static method. Typically, only the top layer of soil ends up being compacted to any degree when using static force.
Dynamic Force
The second type of force used in compaction is dynamic force, where the compaction machine uses its own weight but with some other mechanism that amplifies the downward force of the equipment. The dynamic compaction mechanism is engine-driven and results in two primary methods of delivering compaction force:
- Impact compaction: The compactor drives its force downward into the soil, impacting it with a solid, flat pad. Typically, impact compaction is delivered in a rapid sequence of blows into the ground, reaching deeper layers of soil with each impact.
- Vibratory compaction: Applying a vibratory mechanism across the soil shakes the particles and causes them to settle closer together, producing higher density compaction. The vibration is delivered typically through a plate, which breaks up soil pieces to allow the particles to fill voids within the substrate.
Different compactors capitalize on the different methods of delivering compaction force, and some combine multiple types of force into one application. The right type of compaction force for your project depends on the type of soil, the depth of compaction required and how dense you need the soil to be.
Types of Light Compactors
Contractors have different types of light compactors to choose from, depending on the method of compaction force they desire and the type of project. In light compaction, you have two broad choices between upright, space-saving rammers or wider, walk-behind vibratory plate compactors.
Some designs combine multiple types of compaction forces, while others use either impact or vibration. Depending on the project, using both rammer and plate compactors can increase efficiency and produce a better quality end product.
Below is a comparison between the three general types of light compactors to choose from.
Rammers
Rammers, also known as tampers, are a type of light impact compactor with an upright design. They capitalize on both the static force of the machine's weight as well as the dynamic force of the rammer's small endplate. Sometimes called jumping jacks, rammers jump up and down vertically on the soil surface, ramming the unit's base into the ground, impacting it repeatedly.
Their slim, vertical design makes rammers desirable for use in small, confined areas, allowing operators to precisely focus compassion in one specific area for more direct work.
Rammers are suitable for use on various types of soil, but they're best known for their effectiveness in compacting soils that are already cohesive or semi-cohesive. This makes them particularly useful in trenches, ditches and along roadsides or wherever you need to create a deep hole or spot for backfilling. Rammers are also useful in preparing foundations because they're able to compact multiple layers of soil that can be further added to strengthen the substrate.
Because rammers use downward force directly over one focused area at a time, they're the preferred type of light compactor when you need to achieve greater compaction depths and drastically increase soil density.
Plate Compactors
Plate compactors are a type of light compactor that uses both static and dynamic vibratory forces to compact soil. These heavy machines come equipped with a large plate surface that's wider than a rammer plate. The plate is maneuvered across the work area as it vibrates the ground repeatedly. This locks the soil into a dense and compacted state.
Plate compactors resemble a push lawnmower, where the operator walks behind the machine, holding its handlebar, as the vibratory plate operates ahead. Because these machines are heavier and wider, they cover a larger surface area compared to a rammer.
Plate compactors are also more suitable for granular soils that need to be shaken apart and settled to release voids between the particles. Plate compactors are excellent at vibrating substrate material into its desired place, particularly over larger, flatter work areas.
While rammers are useful in tight and uneven locations, such as trenches, plate compactors are better suitable for surfaces that have already been graded and leveled. However, plate compactors are still light-duty machines, meaning they can be maneuvered in narrow spaces, unlike heavy-duty construction equipment.
Plate compactors come in a variety of shapes and sizes. They offer an ergonomic design that prevents repetitive and strenuous movements and limits stress on the operator's body.
Vibratory Tampers
Vibratory tampers are rammers with vibratory plates. While conventional rammers rely on the machine's static weight and the impact of its plate to compact soil, vibratory tampers also function like a plate compactor, offering both vibratory and impact compaction in a single unit.
When you need the slim, upright and maneuverable design of the rammer but with the vibratory functionality of the plate compactor, a vibratory tamper provides the best of both. Since impact rammers work well on cohesive soil and plate compactors work well with granular soil, vibratory tampers provide a ramming solution in work areas with a less cohesive substrate that needs to be highly compacted.
Vibratory tampers are applicable in roadworks, landscaping and utility installations because they're useful on a wider variety of substrates and maneuverable in creating trenches, ditches and irrigation lines. They also provide compaction in highly focused areas. If you need to compact next to a structure such as an existing foundation, you can achieve deep and tight compaction easier than with a plate compactor.
Vibratory tampers often come with an ergonomic handle that reduces vibration through the operator's hands and arms, preventing strains and injuries.
Light Compactor Applications
Many different sectors need soil compaction equipment and techniques to function. Soil compaction in construction, landscaping, mining and infrastructure installation improves the strength and stabilization of the ground, ensures long-term structural integrity, minimizes future repair and maintenance costs and protects the safety of those working and using the area.
Below are the different applications for light compactors across various industries.
Construction
Soil compaction is a critical aspect of site preparation prior to construction. To build a proper foundation, construction lots need to be properly graded and leveled, but they also need to be adequately compacted to provide a sturdy base. Soil compaction reinforces the substrate and stabilizes it to establish a proper foundation.
Whether residential, commercial or industrial construction, buildings are only as solid as their foundations. Proper soil compaction in construction prevents issues like:
- Soil erosion
- Concrete slab cracks
- Pipe leaks
- Structural loss
Thanks to proper soil compaction, buildings have much better structural integrity. This helps reduce construction and maintenance costs and minimizes costly re-work.
Landscaping
Landscaping contractors rely on soil compaction techniques to prepare lots for landscape installations. Landscapers must compact certain consistencies of soil to smooth and level it out for planting or installing walkways or irrigation lines.
In landscaping, it's important to use the right light compaction techniques to produce adequate soil density for stability without over-compacting the soil, as that would prevent moisture retention or organic matter from growing. Highly compacted soil cuts off water, nutrients and oxygen from reaching plant root systems, so having better control over compaction allows landscape contractors to achieve the right density.
Contractors use precise, light compaction equipment, such as rammers, to properly shape and firm up the soil. Having better control and focus over soil compaction helps prevent compacting various soil types too densely.
Mining
Soil compaction is an essential practice in mining and other industrial operations. Highly compacted soil reinforces the earth around the mine or quarry, increasing its load-bearing capacity so the work zone can withstand the repeated passing of heavy trucks, equipment and foot traffic.
High-density soil compaction reduces the presence of any pores or voids where water can seep into, preventing a large buildup of pressure that can erode the soil and cause a collapse. Similarly, tightly compacted soil along sloped areas can prevent the ground from shifting under the weight of repeated traffic. This prevents sloped areas from giving out, greatly reducing the risk of accidents along embankments or walkways.
Infrastructure
Infrastructure projects, like road, rail or runway construction, rely on the essential process of soil compaction. Highly compacted soil provides an adequately strong and flat base to support the pavement or infrastructure installation, ensuring it remains stable over time.
Almost all roadways contain a soil substrate underneath them, which has been compacted heavily to prevent expansion and erosion during the construction process or afterward during maintenance and reclamation. This reduces the risk of road washouts during heavy flooding, where water seeps into any available void within the substrate.
Additionally, tightly compacted soil minimizes damage from the freeze-thaw cycle in colder climates that often causes roadways, sidewalks, parking lots and other infrastructure to expand and break apart. This reduces long-term maintenance, repair and replacement costs and saves jurisdictions on these major expenditures over time.
Considerations for Selecting a Light Compactor
When selecting a light compactor rental for your construction, landscaping, roadwork or mining project, consider a few crucial factors. You want to choose the right model for the substrate as well as the project size, factoring in any space constraints or unique terrain characteristics.
Operating compactors can also be physically demanding, and these heavy pieces of equipment can pose a safety risk if improperly applied. You'll also want to consider any transportation and operation limitations so you can select the appropriate size and type of compactor.
Below is an overview of the top factors to consider when choosing the right light compactor for your project.
Soil Type
The first factor to consider when choosing a light compactor is the type of soil you need to compact. In general, soil is either cohesive or granular, differing in the size and coarseness of the individual soil particles:
- Cohesive soils consist of silt and clay, with very fine individual particles that feel smooth to the touch. When moisture-rich, cohesive soils can be easily molded and shaped. When dried out, they clump together and are difficult to crumble. To compact cohesive soils, you need repetitive high-impact force to squeeze out any moisture and remove the voids. Rammers and vibratory tampers are the best types of light compactors for cohesive soils.
- Granular soils are composed of gravel and sand, with each granule visible to the naked eye. These non-cohesive soils crumble apart easily but contain large spaces between each particle. To compact granular soils, you need vibratory forces that shake the granules so they fall apart easily and settle evenly. After repeated vibration, the granules lock into place, reducing the pore sizes between each particle. Plate compactors are suitable for granular soils and help achieve firmer compaction than impact force alone.
Project Type and Size
When choosing a light compactor, it's important to consider the unique aspects of the project. The larger the project area and coverage needs, the bigger the plate you'll need. Likewise, bigger compactor plates are able to get more area covered in less time, helping you meet your production goals sooner.
Plate compactors cover more surface area, but the potential tradeoff is a smaller compaction thickness. Since vibratory plates lift the material from the bottom up, it's important to know the thickness of the soil being compacted to ensure it gets the full compression it needs. For thicker compaction, you may want the impact force of a rammer.
Safety and Transport
Compaction equipment can be strenuous to operate, so it's important to select the right model for the operator's level of comfort and experience. Though light compactors are considered small equipment, you might choose a model that is most maneuverable and easy to operate to reduce job site safety risks.
Similarly, you'll need to consider how you plan to transport the compactor to, from and around the job site. Plate compactors are heavy pieces of equipment, so be sure to have the proper lift mechanisms available.
Light Compactor Brands Available at The Cat® Rental Store
A final consideration when selecting a light compactor rental is where you can rent top compaction equipment from leading brands. At The Cat® Rental Store, we carry a wide range of both impact and vibratory light compaction equipment from reputable brands, including Multiquip, Wacker Neuson and Weber.
When choosing a light compactor manufacturer, consider the type of technology and safety features integrated into the various models. Since over-compaction is a top concern when compacting soil, manufacturers have developed technology that helps operators compact soil properly while ensuring high productivity. Many of these manufacturers offer built-in compaction control systems that prevent making too many passes that lead to over-compaction.
Below are the light compaction equipment manufacturers you'll find offered at The Cat Rental Store:
- Multiquip: Multiquip's Mikasa rammers and plate compactors are designed with high-quality engines that deliver ample force into the plate mechanism for strong and even compaction. Mikasa's Compas technology system alerts operators when a soil stiffness threshold has been reached, preventing operators from making unnecessary passes and saving them time and effort.
- Toro: Toro plate compactors are light compaction equipment designed for tough jobs, including compacting trenches with mixed or granular soil as well as asphalt.
- Wacker Neuson: Light compaction equipment from Wacker Neuson is equipped with Compatec compaction control technology that helps operators keep track of their progress and alerts them to over-compaction. Wacker Neuson compactors help operators work more efficiently and productively.
- Weber MT: Weber MT manufacturers impact and vibratory compaction equipment that's high-performing and efficient. The built-in Compatrol compaction control system reduces the number of redundant passes so operators can get more done in less time.
Today's light compaction equipment has come a long way. With advanced technology and safety features, compacting soil to the right density and level has never been easier or more cost-effective.
Find Light Compactor Rentals at The Cat Rental Store
When you need high-performing and efficient light compaction equipment for your construction, landscaping, mining or roadworks project, The Cat Rental Store is your top source for high-quality equipment rentals. Our inventory of light compaction equipment is available to get you working quickly and productively and at a cost-effective rate. We also carry a range of other compaction equipment, including asphalt compactors, ride-on rollers and walk-behind rollers.
Whether you need light compaction equipment, like rammers and plate compactors, or heavy-duty solutions for compacting bigger surface areas, The Cat Rental Store near you can help you complete your next project safely and productively. Visit one of our 1,300 global locations today and get expert advice from one of our rental specialists. To inquire about a rental online, fill out a Quick Quote or call us at 1-800-RENT-CAT for immediate assistance.
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