Marini''s new Voyager asphalt plant is a development from the ART220 mobile hot mix plant featuring new and more sophisticated technology. This self-propelled, parallel flow machine features a high degree of automation and dries and heats recycled materials and allows efficient compaction.

Using this method removes moisture from the recycled material and allows a good bitumen coating for the stone. In some applications, up to 20% of new materials can be added, while the milling depth can be controlled as required. The finish quality is said to be as high as with material supplied from a hot mix plant, but conventional recycling trains have required high temperatures that result in high emissions of water vapour, CO2 and dust.

However a patented new technology from Fayat tackles the shortcomings of previous recycling trains. Instead of operating at 150°C, Fayat''s new mixes mean the asphalt plant can operate at lower temperatures, which almost eliminate any emissions of dust, fumes and steam. Trials have been carried out so far in Spain, Canada, Italy and France in a variety of weather conditions and applications. Sales and marketing manager Jacques Bonvallet said: "We are coating the product with bitumen emulsion, so we call this warm bitumen emulsion."

A key to the process is the way the aggregate is heated to 90°C and foamed bitumen is then injected at medium pressure. Water contained in the foam is vapourised but the system does not generate the large quantities of steam, CO2 or dust of previous techniques. Output is over 200tonnes/hour (and Bonvallet reckons outputs as high as 250tonnes/hour could be achieved in some duties) and this technique has already been proven in field tests. Bonvallet said: "It is a mix of old and new technology and will give a new start to our Voyager recycling plants. In the past we had a problem with the recycling train because it produced smoke, dust and exhaust emissions."

Because the new technology uses reduced temperatures, it offers savings in fuel costs too and Bonvallet reckons the system offers customers several advantages over conventional technologies. Bonvallet added, "Low energy asphalt has generated interest but so far it''s not been successful so far. This offers a better solution."