Road rollers or compaction rollers are some of the most low-key construction machines out there. They’re not used on as many projects, and their main use is to prepare or finish foundations. This means that they aren’t as visible to the public as other types of construction equipment. That being said, a road roller is still a valuable part of many road construction and residential construction projects – just like dozers, excavators, skid steers, or any other piece of construction machinery.
What Is a Construction Roller?
A construction roller is also known as a road roller, compaction roller, or steam roller. Although these machines are not powered by steam anymore, they used to be and in some cases, the name stuck. A roller at its essence is a really heavy wheel that is used to level out and compact terrain, soil, dirt, asphalt, or any other kind of foundation or base material. There are a few different types of rollers including single and double-drum rollers. There are also Padfoot and vibrating rollers.
Why Does Compaction Matter for Construction and Foundations?
The main purpose of using a compaction road roller is to create a more solid and stable foundation for projects. If the particles of soil or asphalt are pushed together to pack them tight to each other, it reduces the chance of shifting, crumbling or sinking. For foundations, it has a huge implication on the stability of a building. In road construction, it makes the difference between the quality of roads, how they last through different seasons and the long-term fixes that will be needed.
Rollers and Agriculture
The first roller wasn’t used in construction. Traditional rollers were used in farming to help break up big chunks of dirt and soil after land was plowed. Horses would be used to pull a solid circular roller behind them so the weight of the roller would help smooth and even out the farmland. Today, these rollers are pulled by tractors or other machines.
Flat and even land is better for weed control and also helps to make the harvesting process easier in the fall.
The Catch 22 of Rollers
The interesting thing about rollers is that in order to be more effective they must be heavier. More weight causes more compaction. While this may seem obvious, it did set limitations to the machine in the past. Horses, for example, couldn’t pull a really heavy roller. The compaction ability of this first roller limited its use.
When steam engines became more common, rollers could get heavier. Their applications expanded beyond farmland and were seen in road construction. As vehicles got heavier and stronger, the weight of rollers could increase. Today, rollers can weigh anywhere between 1 and 20 tons. 20 tons is the weight of about 3 and a half elephants.
Single VS Double Drum Construction Road Rollers
The main difference between single and double drum construction rollers is clear in their names: one has a single roller and the other has two. The impact of this difference makes each type of roller better suited for specific jobs and terrain.
Single Drum Construction Rollers
Single drum compaction rollers have a single large roller dum on the front and wheels at the back. The wheels on a roller machine are specially designed to be puncture resistant and to offer a good grip on smooth terrain. The wheels at the back give this machine good traction and mobility. It can move faster since it only has a single drum at the front.
Single drum rollers are often smaller than a double drum which means it can work in tight spaces and on smaller projects.
Single drum compaction rollers for construction are often used for prep work and ground leveling. They are popular machines for highway and residential road paving as well as foundation building.
Double Drum Construction Rollers
As the name suggests, a double drum roller is an operator’s cab with two rollers attached to it. There are no traditional wheels on a double drum compaction roller. This roller leaves a smooth surface both in front and behind which helps when finishing projects. The second drum adds a lot of extra weight to the machine which helps it compact soil, dirt, or whatever other material it drives over.
The double drum does have a disadvantage. Without rubber-tracked tires, this machine has next to no traction. It is not created for specialized work and should only be used on even or very gradual slopes. However, the double drum is incredibly powerful. With two drums it does double the work when compared to a single drum.
The efficiency and power of this machine make it great for heavy-duty jobs such as laying asphalt for highways.
Padfood or Sheepsfoot Rollers
While most drum rollers are smooth there is a specialty type of roller that is not. A Padfoot or sheepsfoot roller has a variety of parts that jut out of the roller, creating a checkered pattern of compression points. The extra space to push down helps to compact soil and dirt much more than a smooth drum dows. It helps to stop the soil from displacing when put under pressure so that material is truly pushed down and together.
Padfoot rollers are popular for compacting fine-grain soil or for fortifying a fountain at a higher level than a smooth drum roller.
Vibration Compaction Rollers
As technologies behind compaction advanced the construction industry was introduced with vibrating rollers. Traditional rollers use weight to push the particles of soils, dirt, etc together through force. Vibration helps this process by “shaking” the particles together so they fit closer and be compacted more intensely.
Think about when you’re trying to pack nails into a box. If you just try to push them down and slam the lid closed, you may have some shift into a better position so you can successfully close the box. However, if you shake the nails around, they will shift and fall into each other easily. Ideally, the box should close with no problem. A vibration roller uses this technology to help create more solid and stable foundations.