Huge earth-moving machines must be used to create a solid foundation before a road can be constructed. Without a solid foundation the road will fail long before its expected lifespan.
Southeastern Site Development uses equipment such as bulldozers and graders to create a level surface that will support a road for many years to come. Gravel is added in layers and machines roll over the surface to compact and flatten it further. Drains and storm sewers are also installed at this early stage, so that rain will drain away from the road surface and make it easier for vehicles to travel in storms.
Once the foundation is finished and has been inspected, the road can be paved. The most common material used for paving roads is asphalt or concrete. Factors such as cost, type, and amount of traffic will determine which material will be used.
Asphalt uses an oil-based substance called bitumen to make sand and crushed rock stick together like glue. After the asphalt is heated to about 300° F, it is transported to the construction site, where construction crews spread and compact it onto the foundation already in place.
Concrete also uses sand and crushed rock, but it’s held together with cement. Workers must pour liquid concrete into special steel molds called forms. As it dries, a finishing machine vibrates it to make it settle evenly and then trims it to the correct height.
To prevent cracks, Southeastern Site Development workers make cuts — called joints — between concrete slabs. These joints allow the concrete slabs to expand and contract with changes in temperature without breaking.