Rehabilitation with the cold recycling paving train
In Tangshan City, a metropolis with a population of 7.7 million, the Yingxiang Road, one of the most important road links between several communities in the city’s Guve district, was earmarked for rehabilitation. The road has an overall length of 4.8 km, and serves as a bypass for China National Highway 205. The original layer structure consisted of a 20 cm cement-treated crushed stone base course and a 4 cm surface course.
A part of the existing base course was milled of together with the entire surface course and mixed with thecement and foamed bitumen as binding agents in the mixing chamber of the Wirtgen W 240 CR cold recycler to produce a new, 10 cm, cold recycling layer that was followed by a new, conventionally mixed surface course with a thickness of 5 cm. The ideal ‘recipe’ for the cold recycling mix was determined beforehand by laboratory analysis. For this purpose, Wirtgen offers the WLB 10 S mobile laboratory unit, which enables the precise definition of the quality of the foamed bitumen.
The complete recycling of the existing road construction materials and the minimisation of site logistics make the cold recycling method environmentally friendly and particularly cost-efficient.
Lateral pre-milling extends the working width of the W 240 CR
The project brief was the rehabilitation of the Yingxiang Road over a width of 6.5 m. The 2.35 m milling drum of the Wirtgen W 240 CR cold recycler is actually not wide enough to enable the completion of the job in two passes. This was, however, made possible by the addition of a Wirtgen W 100 H small milling machine to the paving train. This machine drove ahead of the cold recycling paving train and milled off a strip at the side of the road to the required depth of around 15 cm. The W 100 H deposited this additionally milled material on the road surface so that the Wirtgen W 240 CR cold recycler was able to take it up and incorporate it in the mixing process.