Asphalt pavers: how roads are laid

An asphalt paver (paver-finisher or asphalt finisher) receives hot mix asphalt from trucks or a feeder, spreads it to the required width and thickness and pre-compacts it with a heated screed. Rollers follow to finish compaction.

How a paver works

1. Trucks tip asphalt into the hopper at the front.
2. Slat conveyors carry the mix to the rear.
3. Augers spread it across the full width in front of the screed.
4. The screed, a heated, vibrating and tamping plate, floats on the mix and sets the thickness and smoothness.

The screed's tow points and angle determine the layer thickness. Grade and slope control systems (sensors, ski beams, or 3D) keep the surface level.

Tracked vs wheeled pavers

• Tracked pavers give maximum traction and smoothness on soft bases and wide highway work.
• Wheeled pavers travel faster between jobs and suit urban streets and frequent relocation.

Screed types

• Extending (variable-width) screeds hydraulically extend for varying widths, popular for urban and general paving.
• Fixed (rigid) screeds are assembled to width with bolt-on extensions, used for highway and airport work where the highest evenness is required.
• High-compaction screeds with tampers and pressure bars achieve higher pre-compaction.

Paving classes

Mini pavers lay 0.5–2.5 m (1.6–8 ft); medium pavers 2.5–9 m; highway-class pavers up to 13–16 m (43–52 ft) with fixed screeds.