Important precondition for long lasting road surfaces is a proper cohesion between each layer.
A complete and durable cohesion between the layers assures that the package of road courses will stand the permanent load everlasting. The layer composite results from cohesion, adhesion and mesh between the courses.
Centre joints result from applying two hot-mix courses aside each other “hot to cold” – no matter whether length – or crosswise. Hot bitumen sprayed onto the joint of the “cold” hot-mix course will create a perfect joint-sealing to the “hot” new hot-mix course to be applied afterwards.
Sealing of the flanks of the asphalt road. To avoid the water penetrating into / between the asphalt courses they get sealed by spraying hot asphalt – up to 4 kg/m.