Asphalt is commonly mixed with aggregates for added strength and traction. The asphalt and aggregates are usually mixed and heated at a central location. The material is then transported to the construction site, where it is spread directly over the base course or top course and compacted. Asphalt surfaces are fairly easy to construct and repair. Concrete, or rigid, pavements are made from a mix of portland cement and aggregate.
Concrete pavements have a long life and require little maintenance.
Concrete is generally laid as a single thick layer directly over a base course. Concrete is usually laid in long sections or slabs of varying length. Metal bars or dowels inserted into the edges of the slabs help connect the joints where one slab ends and another begins. When the ground underneath expands and contracts from seasonal or weather changes, the concrete becomes prone to cracking. Cracks can occur at or near the joints where concrete slabs meet or on the slabs themselves.