PURPOSE: To make it possible to separate surface tar from the surface of an asphalt layer by spraying a cooling medium to the surface of the asphalt layer from a nozzle and striking the surface of the layer with a separation member equipped with a plurality of blades to be mounted on a rotary shaft.

CONSTITUTION: During the running of an equipment body, liquid nitrogen is sprayed to the surface of an asphalt layer from a nozzle. After the heat is cooled, aggregates and tar on the surface are contracted. A shearing stress works between the aggregates and the tar by a differential thermal shrinkage. What is more, the surface is hardened with the cooled tar and Young module is increased. The cooled and hardened surface is struck with blades 25 of a separation member which is subsequently to a nozzle. When the tar is compacted while the blades 25 are repelled, a tensile stress is produced and works to separate the surface tar. During the operation, the blades 25 are arranged to be displaceable longitudinally only by a dimensional difference between a shaft 28 and a long hole 26 with a rotary shaft 10. Then, the blades 25 are displaced in the projection direction by a high speed rotary motion of the rotary shaft 10 so that a corner part 25a is collided against the surface of the asphalt layer. After the collision, the blades 25 are inwardly displaced so that it may be separated from the surface.