Cold milling machines have real bite.

Replacing the pavement is one of the standard methods in road rehabilitation. What are the challenges posed by this rehabilitation method? What machines are used for replacing the road pavement? What are the methods used for building a new pavement?

The challenge of road rehabilitation lies in removing only those layers of a road structure that are actually damaged. Additional conditions frequently stipulate that the flow of traffic must be maintained in spite of extensive reconstruction measures. In view of these prerequisites, the choice of suitable rehabilitation methods in a construction project is often narrowed to one single option: removing the damaged pavement layers by means of cold milling machines.

Milling and loading in one operation

The tools that cold milling machines use for removing road layers were originally developed for the mining industry. So-called point-attack cutting tools, fitted to a rotating milling drum on the underside of the machine, bite into the road at precisely the specified depth. No material is too hard for these tools: Cold milling machines are even capable of rehabilitating concrete pavements. Whether asphalt or concrete: The material is milled and then directly loaded on trucks to be transported from site, all in one single pass.

Ahead of the traffic jam

Because traffic is often slow-moving in the area of the job site, car drivers mock the massive cold milling machines by saying that they’re always first in the traffic jam. Few bear in mind, however, that rehabilitation projects using cold milling machines are mostly carried out as mobile roadworks. Alternative methods would involve a much greater effort. Cold milling of road pavements is unrivalled in terms of both logistics and speed of execution.

Road milling machines are team players

Not all cold milling machines are as big as a whole apartment. Some models are as small as a passenger car. On many job sites, machines of different sizes frequently work as a team, each one playing its own aces: The large milling machine removes the large surfaces, while the small one takes care of milling off the pavement around “nuisances”, such as manhole covers or kerbstones.

Paving and compacting using pavers and rollers

Typical of rehabilitation methods using cold milling is that the damaged pavement layers are usually replaced with asphalt – irrespective of whether the distressed pavement consisted of asphalt or concrete. The new surface course or asphalt road structure is paved by road pavers prior to conventional compaction by rollers.