Asphalt pavers are large pieces of construction equipment used for paving roads and other outdoor surfaces. After new roadways have been graded and a base layer of gravel has been installed, a paver is used to lay the asphalt. This asphalt mixture is made from a sticky crude oil by-product mixed with gravel and other aggregate materials. The paver distributes this mixture across the roadway and helps to form and shape it. A rolling machine follows the paver to further smooth and compact the road surface.
There are two main types of asphalt pavers that buyers may select from. The first is a compact unit, used for parking lots and other small paving jobs. These 3-20 horsepower compact units are not self-propelled, and instead must be towed behind a dump truck or tractor. Smaller units work well for narrow spots, but don't usually have the power to pave wide sections of roadway in a single pass.
For larger projects, self-propelled asphalt pavers are used, and may range from 100 to 250 horsepower. These units consist of a tractor and a screed. The tractor is used to steer and propel the paver, and also to distribute the asphalt. Dump trucks are to fill the paver with aggregate before the job begins, and heating and mixing mechanisms within the paver help keep the asphalt blended and at the correct temperature.
The screed on an asphalt paver helps to shape and level the surface in preparation for the rolling machine. It contains vibration units and a number of complex sensors that allow it to self-adjust, keeping the roadway as smooth and compact as possible. Using controls on the tractor, the operator can automatically widen or narrow the screed as needed for different sections of road. On smaller asphalt pavers, the screed may be placed on the front of the vehicle, which provides better control and handling. With most larger projects, however, the screed is towed behind the paver as this allows wider areas to be paved more easily.
When choosing an asphalt paver, another option to consider is whether to use a wheeled or tracked unit. Asphalt pavers with wheels provide excellent speed and mobility, but often don't have the power to pull a wider screed. Machines on conveyor tracks, on the other hand, will not move as quickly or as easily, but offer superior traction, allowing them to make wider pulls.