On the surface, soil compaction is pretty straightforward — a vibrating drum agitates soil particles until less air exists between them, creating a more stable structure. The machines that perform this task seem rather simple, as well. However, today's manufacturers are working hard to bring you models that are more productive, simpler to maintain and easier to operate.
According to Sakai America, vibratory soil compactor brands are available in a range of drum widths from 39 to 85 in. Frequency ratings typically range from 1,500 to 2,400 vpm, while the centrifugal force generated can range up to as much as 90,000 lbs.
The most popular size class of soil compactor tends to be a single-drum unit with an 84-in. drum. However, there are various features you should consider before choosing a size and configuration for your fleet. There are a number of specifications to compare, including operating weight, rolling width, drum amplitude, dynamic force and pli (pounds per linear inch) rating. But you should also take into account some of the latest technologies that can set certain machines apart from others.
Doing it smarter
Many compaction equipment manufacturers have introduced automatic vibration control systems to help facilitate the most productive and efficient compaction performance. These systems work by utilizing a directed exciter mechanism so the roller automatically adjusts the output energy of the drum to optimize compaction. This allows the operator to know when maximum density has been achieved, eliminating unnecessary passes and over compaction of the soil.
While this technology increases the acquisition cost of the machine, manufacturers argue that it pays for itself by increasing productivity. Steve Wilson, manager marketing services/product manager at Bomag Americas Inc., notes that automatic vibration control technology offers several advantages. "It minimizes the time needed to achieve maximum results, there is no over compaction and it allows for proof rolling to find weak spots," he explains.
Machine control systems for enhanced traction and gradeability are another area of advancement. According to Wilson, systems such as these monitor the slip potential between the drum and rear rubber tires, then automatically adjust the hydraulic flow to deliver optimum performance for operation on severe grades or difficult traction conditions and to prevent the roller from stalling or "digging" itself into the material.
Enhanced climbing capability
Because soil compactors are being asked to perform at steeper grades and in challenging underfoot conditions, many suppliers have incorporated specialized traction control systems designed to improve the gripping ability of these machines.
For example, Ingersoll Rand has incorporated the Ultra-Grade traction control system on many of its mid-size and larger models. The Ultra-Grade system is designed to help ensure the compactor's ability to climb and maneuver in tough soil conditions. Heavy-duty axles with no-spin differential further enhance traction and climbing capabilities.
Sakai America has come up with an even more unique solution in the form of its track-driven CV550 soil compactor. The CV550's track drive system incorporates a traction valve that regulates power between the drum drive and track drive. A balanced weight distribution and no-spin differential further enhance climbing capability. Such features combine to deliver the traction and gradeability to climb slopes up to 45° while compacting.
Lower fuel costs
Everyone wants their equipment to be more economical, particularly the larger units that cost a lot to fuel. To this end, some soil compactor manufacturers are incorporating features specially designed to optimize fuel consumption.
For example, Bomag has incorporated an Eco-Mode on its Dash 4 Series. These machines offer three throttle positions, including one for idle, one for maximum rpm and another for Eco-Mode. "The engine senses load demand and adjusts the engine rpm to meet the needs of that demand," explains Wilson. "As a result, the engine consumes less fuel and there are fewer emissions and noise."