One of ways to repair patch is:
A cut-off saw with dust suppression slices through the old bitmac. The bottle feeds water to the blade to ensure dust is tuned to a slurry. Pumping the bottle recharges the pressure which keeps the water flowing.
Next, a breaker (jackhammer) is used to break up the old surfacing, which is dug out & disposed of safely. The exposed sub-base has been tidied up & compacted.
So now a layer of base macadam is spread out & levelled. The base course (aka binder course) has a chunky 20mm agg for strength.
It is raked out to a level which will allow 25mm of surface course to cover it. Any spilled loose materialis swept off the existing surface & then the roller is brought in to smooth & compact the bitmac.
Note: Water is dripped onto the roller drum so that the bitmac doesn’t stick on it.
It is imp to ensure thorough compaction to minimize later settlement.
Once the base is compacted, the surface course (wearing course) can be added.
For trafficked areas, generally 25mm thk layer is used of the surface course. The surface layer is finer, using 6mm or 10mm hard agg’s to give an even surface & that evenness depends on the skill & dexterity of the rake-hand.
The barrowman brings in hot macadam & places it where directed by the rake-hand who use the rake to spread the material to where its needed, & to level it out. Turning the rake upside down helps to achieve an even & smooth finish & then once again, loose material is swept off the existing surface to prevent it being crushed & damaging the old macadam.
The roller is brought back & used with NO vibration on the first passes, as this helps compact the surface without causingit to stretch. Again, water on the drum prevents the mac sticking to the roller.
Once all the surface has been rolled, the vibration can be switched on to ensure good consolidation. 6-8 passes over each part of the new surface should be adequate