When choosing a compaction machine, an important consideration is whether to purchase a vibratory or oscillating roller. Both systems have advantages and disadvantages, so it is important to understand the differences so you choose the right machine for your job.
Vibration
Traditional vibrating rollers are equipped with one or more weights rotating on one shaft in the center of the drum. When the mechanism rotates, the drum begins to vibrate, causing compaction forces in a downward direction to the soil. This is what typically increases the compacting force up to six times the actual static weight of the drum assembly itself, allowing for greater compaction with fewer passes. However, due to the up and down movement, the roller drum is not in contact with the ground for up to 50% of the time it is in motion.
Oscillation
An oscillating roller is equipped with two rotating weights placed away from the center of the drum, which generates an oscillatory motion. This means that, opposed to a vibratory roller, the drum does not move its axis of rotation, but rather oscillates around it. These changes in force provide compaction energy both horizontally and vertically to the front and rear of the drum. Unlike a vibratory roller, the oscillating roller does not lift off the ground and maintains constant contact with material.
Which is best?
Vibratory rollers have long been the workhorse of the compaction business, and have a history of providing excellent results. These machines are able to achieve uniform compaction with a wide variety of materials, and produce good depth effect.
Oscillating rollers have recently started to gain more widespread use due to their benefits. These rollers provide continuous ground contact to reduce the number of passes needed compared to vibratory machines. In addition, they offer a higher degree of compaction without destroying the granular structure of the asphalt. Simply put, you cannot over compact with an oscillating roller. Finally, they produce a perfectly smooth surface, and provide optimal, dynamic compaction all the way to the joint without harming the cold road surface.
If both systems offer benefits to your business, or if you can’t decide, Sakai manufacturers machines that have both options on one machine. The Sakai SW850ND is one example of a machine that offers the best of both worlds, and may be the perfect solution for your business.
