a. A hole with a diameter of min. 114 mm and a suitable depth needs to be drilled into the subgrade with a core drill so that the drill always enters the dry road surface at a right angle.
b. The depth must be controlled by adjusting the height adjustment mechanism on the drill. The adherence to the specified hole dimensions should be checked at regular intervals.
c. The drill depth has to be checked on the first hole drilled. Make adequate adjustments when necessary.
d. Ensure that the drill does not damage the surrounding road surface when extracted from the hole
a. Remove the core with core removal equipment. When using hammer and chisel, place the chisel at the bottom of the core to force the core out as a whole. Make sure that the adjacent asphalt is not damaged.
b. Instead of drilling, the hole can also be milled into the subgrade using a suitable milling tool. To ensure the adhesion, the abovementioned dimensions of the hole must be strictly observed.
a. Clear the hole and the surrounding area of dust and core parts using a compressed air hose.
b. Remove any gravel that makes the hole base uneven. Use a stamper to ensure that the bottom of the hole is perfectly flat.Make sure that the surface is absolutely dry and free of oil and grease.