In-situ Cold Recycling
Cold in-situ recycling is an increasingly popular choice of road maintenance and rehabilitation for the local and regional roads chosen by the Road Engineer. With bitumen emulsion added to a cold recycling treatment, a structurally rehabilitated layer is created that is flexible and fatigue resistant. Once cured, it is moisture resistant and rut resistant.There is no need for additional aggregate materials to be added. (Extra material can be added to make up levels if required)
Cold in-situ recycling as its name implies, involves the reuse of the existing road pavement material. It is termed a cold process as the binder used is in the form of a bitumen emulsion and consequently, the aggregate does not require heating. As a result there is lower fuel demand and less carbon emissions.
The process starts by determining the depth of material to recycle.The depth will vary depending on the available depth of suitable recyclable material in the road make up (Clause 804/806). Allow a depth of 150mm to 300mm for the recycling process. A sample of this material will be taken from the road ideally by using a mini milling machine so as to replicate the fullscale recycling process.These samples will be sent to a laboratory for analysis to determine the materials gradations, the binder content, the percentage and type of emulsion to be added and the optimum moisture content along with other data.This will give the ideal design parameters for the recycled material. The works on site will commence once the ideal moisture content and percentage of emulsion required for the new layer are determined.
The Operating Principles of cold Recycling
Cold recycling is an economically efficient and environmentally friendly method for producing base layers of superior quality.
The entire Cold-In-Place Recycling Process is done by means of a combination of machinery called a 'Train'.The pieces of equipment used in the train operation are an emulsion tanker, a water tanker, a milling machine, a grader and a roller.The emulsion is added to the milling machine to achieve the required content as in accordance with the mix design.