A. Vibratory roller compactor
These are roller compactors that rely on both the weight of the drum and vibrations to exert compaction force. Vibratory roller compactors are known to deliver better results and faster compared to other roller types.
1. Explanation of vibration mechanisms
The drum on vibratory rollers are fitted with eccentric weights. These weights vibrate when triggered electrically. The weights’ vibrations are then transferred to the drum and finally to the material under compaction. The intensity of vibrations is regulated from a control point in the operator’s cabin.
2. Benefits in compacting different materials
Vibratory rollers tend to achieve better compaction results faster. The vibrations eliminate air voids, densely packing material particles together. This in turn reduces the number of passes needed to achieve the desired density; making them economical.
B. Static roller compactor
Static roller compactors rely solely on the weight of the drum to exert compaction. The drum is attached either at the back or front of the roller.
1. Description of static compaction
The drum on static rollers is lined with heavy material; concrete in some cases, on the inner walls. With this weight, the drum is rolled over compaction material by power generated by the engine. The weight of the drum exerts a vertical force on the material compacting it. The roller passes over the material severally until the required density is attained. The passes overlap to ensure no are is left uncompacted.
2. Ideal scenarios for static rollers
Static rollers are used in projects that require a consistent finish. This includes subbase compaction and asphalt paving. It is also used in landfill management since vibratory rollers could spread toxic wastes increasing risk of environmental pollution.
C. Pneumatic rollers
1. Introduction to pneumatic rollers
Pneumatic rollers are equipped with air-filled rubber tires instead of steel drums. They have two sets of tires at the front and at the back. However, some models have three sets of tires and are applied depending on project requirements.
2. Applications in road construction and asphalt compaction
Pneumatic rollers are used to provide a smooth surface in asphalt paving. The rubber tires provide a smooth interface over which the weight of the roller is transmitted to the asphalt.