Germany-headquartered Wirtgen China reports that studies, made in China and overseas, show that Wirtgen's bitumen stabilized paving recycling technology is reducing the carbon footprint associated with reconstructing China's roads and providing road users with a more durable highway resulting in less traffic disruption.
More and more cities and highway authorities in China are benefiting from Germany-based company Wirtgen's bitumen stabilized paving recycling technology, which conserves energy, reduces the demand for new materials, and produces a more durable road surface.
The Yunnan Highway bureau and the city of Xi'an are two examples of where Wirtgen's technology is being applied and are reporting cost savings and savings in carbon emissions in the order of 30%.
Wirtgen's technology involves milling the existing road paving material and then mixing it with an emulsion or foam of bitumen suspended in water together with a small amount of cement or lime. The bitumen acts as a flexible binding agent coalescing the milled particles together and also limits the ingress of water into the road base since the hydrophobic nature of bitumen inhibits water entering a layer of well-compacted material. Water entering the road base is a major factor in causing roads to deteriorate, particularly in parts of China that are subject to hot wet summers and freezing winters.
Results emanating from applied research efforts (primarily in South Africa, the Netherlands, and the USA) suggest that the energy consumption associated with relaying a road can be reduced by a factor of up to three compared to older and more conventional technologies. In addition the grater durability of roads laid with this technique further reduces the expense and energy consumption associated with road repairs.
The adoption of Wirtgen's technology by the Chinese road authorities for rehabilitating their expressways has opened up new research avenues which promise to be more important than everything done to date. The Yunnan Highway Bureau, for example, has successfully used three Wirtgen WR2500S units and a KMA200 unit, in their rehabilitation of the national highway network. This 800,000.00 square meter recycling job will be completed this year and the road owner is expecting to make cost savings of 30% compared to conventional methods. And Xi'an is using two Wirtgen WR2500S units on their municipal road rehabilitation. Changan Road in the city was repaired in 2009 with cost and energy savings combined and the benefit of reduced disruption to traffic due to a faster turn-round.