Pavement Repair and Rehabilitation
Roads are exposed to tremendous loads that will sooner or later leave their marks on them. A time will come when every road will be in need of a general overhaul. But no two damage patterns are alike.
Which rehabilitation methods offer a cure for distressed roads? What are the differences between them? Which are suitable to be carried out as mobile roadworks?
Replacing the Pavement
Replacing the pavement is a standard procedure when repairing roads. The challenge is to ensure that only the damaged layers of the road structure are removed – and to avoid disruptions to traffic at the same time. Under these conditions, cold milling is the only viable option for many construction projects.
The pavement is removed by cold milling machines. In most cases, machines of various sizes make up a team: the large milling machine removes the bulk of the pavement while the smaller machine takes care of such fittings as manhole covers and edgings.
Whether asphalt or concrete, the machines transfer the reclaimed asphalt pavement (RAP) directly onto trucks for removal in a single operation.
Paving Thin Layers Hot
It is not necessary to replace the entire pavement if only the surface of the roadway shows signs of damage. The method known as “paving thin overlay hot on hot” is a particularly economical and eco-friendly alternative.
A paver with integrated spray module is preferably used when paving the thin overlay. It automatically applies a tack coat of polymer-modified bitumen emulsion to seal the base. At the same time, it paves a thin asphalt surface course just 1.2 to 2.0 cm thick.
Dynamic compaction with oscillation is ideal, ensuring that the underlying cold layer is not damaged by compaction. Static compaction is also possible, but without vibration.
Paving Thin Layers Cold
“Thin overlays paved cold on cold” – better known abroad as “micro-surfacing” – are another quick and cost-effective alternative to replacement of the complete pavement.
Cold milling machines with fine milling drums first prepare the road surface for application of the thin overlay. The resultant fine profile of the milled roadway creates an ideal substrate with which the micro-surfacing can engage. The “valleys” of the fine-milled profile securely engage the layers of the micro-surfacing, thus producing a perfect layer structure.
Thin layers paved cold on cold provide a cost-effective as well as quick solution. The thin wearing course can be paved in the form of a mobile site and the road reopened to traffic within a short space of time.
InLine Pave
InLine Pave has become established as an official construction method according to German regulatory frameworks. The binder and surface courses are paved “in line”, i.e. one after another “hot on hot” in a single pass. Since the machines are just 3 m wide, traffic can continue to flow without obstruction on the remaining lanes.
Very high precompaction of the binder course prevents the binder course material mixing with that of the surface course and ensures clear separation of the layers as well as an optimum surface seal. The bond between binder and surface course is outstanding. The very strong layer structure not only makes application of a bitumen emulsion unnecessary, but also additionally extends the useful life of the road.
