Compaction Equipment - Part 1

The compaction process is described as a mechanical process of increasing the density level in certain ground materials. With this process, the volume of the material is being compressed into smaller volume. The particles within the material that is being compressed move close one to another. This is caused by using specific types of compaction machines. The usage of proper compaction equipment is very important for achieving excellent compaction results on the ground. There are many different types and models of compaction machines from different manufacturers. Each model has its own unique characteristics, and it is used for certain purpose. From small plate compactors to big and bulky roller compactors, every type can be used for achieving great compaction results.

One particular compaction machine that is very popular and it is widely used, especially for asphalt material compaction, is the compaction roller. This particular machine today can be seen on every construction site where the ground needs to be compacted properly so that a nice layer of asphalt can be placed. And after the asphalt layer is placed, the roller compactor is still needed to compact the asphalt mixture. The following text will highlight which are the mostly used roller compactors for compacting asphalt mixtures.

Generally there are four types of roller compactors that are used for compacting asphalt material, and they are:

• Static roller compactor
• Vibratory roller compactor
• Pneumatic roller compactor and
• Combined roller compactor

Static roller compactor. The static roller compactor compacts the materials by applying static pressure. For many years, the static roller compactor was the main compacting machines used for compaction of asphalt mixtures. This roller compactor can be found in different sizes and shapes, and equipped either with two or with three steal wheels or steal drums. The static roller compactor compacts the asphalt material by using weight which is provided by ballast. The drums or the wheels of the static roller are filled with ballast, which can be either sand or water, and in that way a static pressure is being created all over the drums or on the wheels. The compaction effort of the static roller is determined by the amount of the ballast and the contact area. The static roller compactor is not suitable machine to compact materials that are thicker than 40 or 70 mm. Also the static roller compactors do not seek for a soft spots on the materials that are being compacted.

On many road construction projects, the static roller compactor is generally used to finish the rolling procedure of the asphalt material once the desired density of the material is being achieved. The so called “ironing” effect provided by the static roller, makes the surface smooth and also eliminates any previous marks created by other wheels or drums. The finishing task with the static roller must be completed while the asphalt material is still hot enough so that any irregularities can be eliminated with slight movements of the static roller. The temperature of the asphalt material is usually 55-75 degrees. 

Continue reading to part 2...