Première: Major project with WR 4200 in China

A “giant” is at work with precision and impressive efficiency on a section of the 658 km Jingshen Expressway linking Beijing with Shenyang in China’s northeast. The first WR 4200 in China is setting new standards in cold recycling. The motorway–or expressway as it is called in China–which is heavily frequented by heavy goods vehicles, is being rehabilitated to the best possible quality by this high-performance recycler.

What makes this project special is that the underlying hydraulically bound base course is also being recycled in a twostage process involving a KMA 200 and the WR 4200, in addition to professionally recycling and subsequently backfilling the reclaimed asphalt pavement (RAP).

Customer impressed by performance

Cold recycling is nothing new to the new owner of the WR 4200: the Tianjin Goldway Co. already owns several Wirtgen recyclers, including a slurry mixer of type WM 1000. A convinced pioneer of cold recycling, the company purchased its first KMA 200 in 2006 and uses the mobile cold recycling mixing plant for rehabilitation projects with foamed bitumen. In view of its outstanding experiences with Wirtgen machine technology and the top service provided by Wirtgen China, it is therefore not surprising that the company immediately considered purchasing a powerful WR 4200 when another major project became imminent. According to the company’s chairman Mr. Wang, Tianjin Goldway has intensively investigated the possibilities of cold recycling technology since 2005. And with great success, as can be seen from the numerous projects. The technology’s advantages are obvious, according to the company’s deputy general manager Mr. Zhang: “The existing material has been 100% reused. The traffic can continue to flow alongside the traffic lane being recycled. The recycled layer is ready for use immediately after compaction. And the cost of labour is considerably reduced.” Performance and speed are key factors on account of the high traffic volumes in China, as Mr. Zhang confirmed: “The WR 4200 can recycle complete traffic lanes in a single pass. Also the high rate of production is very convincing: the WR 4200 produces 400 t/h. Another important point is that it can even work perfectly at night, thanks to its optimized illumination system.”

Cold recycling from A to Z with foamed bitumen as an innovative binder

In the customer’s new major project, Wirtgen machines will cover the entire cold recycling process chain: a large milling machine of type W 2000 first mills off 24 cm of the existing pavement structure. The RAP is loaded directly onto trucks and transported back to the KMA 200 nearby the job site. It is then processed by adding foamed bitumen and cement, while the pavement is cold recycled in situ by the WR 4200 on the motorway: 18 cm of the base course are recycled with foamed bitumen and cement. The RAP recycled in the KMA 200 is then paved 20 cm thick on top of the recycled base course. In the last phase of the project, a 4 cm thick layer of polymer modified asphalt is paved onto the recycled layer. These efficient processes yield outstanding results.

Active promotion, success in practice

With Mike Yu, Luson Yu and Dr. Alan Shi, Wirtgen China’s team includes three exceedingly competent cold recycling specialists who can advise their customers on every aspect. Then there is the professional after-sales service on site, and the extensive possibilities for repair, maintenance and training offered by Wirtgen China on everything related to the recyclers. Mr. Zhang of Tianjin Goldway also confirmed the importance of this aspect for the new project: “For us, it was vital to rely on the extensive knowledge and experience of Wirtgen China regarding the practical applications. Whenever and wherever we are, we are assured that Wirtgen is always there to support us. Thinking about this, we have every reason to be even more optimistic of the future application of this cold recycling technology using foamed bitumen.” In addition, Wirtgen China is working hard to make its customers more familiar with every aspect of cold recycling technology. The expertise of the Wirtgen Group is being made available directly to Wirtgen China’s customers through seminars with international specialists. These efforts are well received, for cold recycling will become increasingly important for the Chinese market as traffic density increases and more roads have to be rehabilitated.

Job site: Jingshen Expressway, China