Asphalt is a popular road construction material today because of its cost and performance advantages. Natural asphalt was discovered in 1595, but it was not bound with coal tar and used to pave roadways until 1902.
Bitumen, the solid or semi-solid residue of the refinery process to make gasoline from petroleum, quickly replaced natural asphalt in paving. Recently, different synthetic polymers have improved performance and durability. Superpave (an acronym for Superior Performing Asphalt Pavements) is the latest technique for making superior asphalt to withstand adverse load and weather conditions.
Vibratory plate compactor
The 10-12-ton road roller utilizes its own weight to compact the asphalt
Spreading grit on hot tar
The road inspector on a working platform