工人们正在用刀具切割劣化的沥青，并在抛光水泥混凝土上进行修复。

joints in concrete pavement The asphalt is synthetic rubber. to have a firmness Flexible and has good adhesion. in order to hold the concrete slab between the joints firmly Prevent water from seeping through the joints to the structure below which is the concrete floor. Flexibility helps it stick. Shrinkage according to the shrinkage of concrete joints to prevent cracking