Construction Site Report: Wirtgen W 155 CFIs are clustered on the Shanghai-Wuhan Expressway, and the step milling is non-stop

For large-scale milling operations such as the expansion and renovation of expressways, due to the requirements of milling output and efficiency, large milling machines with a 2-meter range are mainly used. However, for high-speed expansion, there is a special type of step milling application that not only needs to meet the milling capacity of a relatively large depth and a certain milling efficiency, but also needs to take into account mobility and safety.

However, in step milling, when the removal width of the water-stabilized layer is narrower than that of the surface layer as per the design requirements, the large-sized body of the 2-meter milling machine, the milling width and the working weight become the shortcomings in such applications.

Since Wittgen first introduced the medium-sized milling concept in the market, its representative models, the W 155 CFi/W 125 CFi, have become a better choice in step milling applications. They are flexible, safe, meet design requirements, and can significantly reduce fuel consumption and save construction costs.

For this reason, in the recent expansion project of the Taicang to Changzhou section of the Shanghai-Wuhan Expressway, more than five medium-sized milling machines have already been put into step milling tasks. Click on the video below and let Xiaowei take you to explore the construction style of the Wirtgen medium-sized milling machine W 155 CFi!

Project Overview

The section of the Shanghai-Wuhan Expressway from Taicang to Changzhou is an important part of the Shanghai-Wuhan National Expressway, connecting southern Jiangsu and Shanghai. It is one of the main entry and exit channels between Jiangsu Province and Shanghai and holds a significant position in the national and regional road network. With the annual increase in traffic volume, the traffic capacity of this major thoroughfare that has been in service for nearly 20 years has become unable to meet the demands of economic and social development as well as people's travel needs.

This expansion project adopts a widening scheme on both sides of the roadbed. The 25-kilometer section from Taicang North Hub to Dongbang Hub will be expanded to a two-way ten-lane technical standard, while the remaining sections will be expanded to a two-way eight-lane technical standard.

The widening of the project road requires overlap treatment with the new road surface. Due to the different settlement conditions of the new and old road foundations, longitudinal reflective cracks are prone to occur at the overlap positions. To ensure the overlap quality and prevent longitudinal reflective cracks on the road surface, it is usually necessary to perform step milling on the original emergency lane road surface and fill and compact it layer by layer.

In addition, the surface structure of the original road surface needs to be milled, and an overall overlay treatment should be carried out in the final stage of construction to ensure the integrity and driving comfort of the road surface after the expansion.

The emergency lane waiting for step milling

Advantage One

"Economy"

The Wirtgen W 155 CFi medium-sized milling machine, with a maximum milling depth of 33 cm, can fully meet the milling thickness requirements of each step in different pavement structure layers. Take this case as an example. It can handle the milling from an 8 cm / 12 cm asphalt layer to a water-stabilized layer of about 20 cm with ease. Compared with large milling machines, the W 155 CFi has a significant advantage in fuel consumption, and the operation cost per shift has decreased significantly. This highly efficient and energy-saving feature enables it to not only meet the requirements of construction design but also create higher economic benefits for construction enterprises.

A total of five layers of milling from the asphalt surface layer to the lime soil layer have been completed, forming milling steps

Furthermore, for the construction party, a smaller milling width means that while meeting the process requirements, the amount of material removed can be reduced. In the face of the current high market price of sand and gravel aggregates, it can save considerable main material costs for subsequent paving construction.

Advantage Two

Flexibility

The ISC intelligent walking system can ensure that the equipment automatically adjusts the speed difference between the inner and outer tracks during milling, making the walking more stable. Compared with large milling machines, the lighter body weight and smaller body size make it naturally more mobile and flexible during operation.

It is worth mentioning that the Wirtgen medium-sized milling machine W 125 CFi can also quickly switch to a 1200mm wide milling rotor during asphalt surface milling through the FCS milling drum quick-change system, achieving a higher milling output. To meet the milling requirements of water-stabilized base layers, it can be flexibly converted to a milling rotor of 600 mm or 900 mm, achieving a faster milling speed.

Advantage Three

Safety

The PTS fuselage attitude control system equipped on the W 155 CFi eliminates the complex operation of manually adjusting the rear outriggers of the machine. It allows the operator to set the longitudinal pitch Angle of the machine or make it parallel to the working surface according to the needs of the construction site, and automatically maintain it during operation.

When entering and exiting the milling pit, the rear outriggers will automatically adjust the machine body posture in accordance with the front outriggers. These automated operation functions can avoid the risks brought by manual misoperation, improve the convenience of operation and the safety of construction. In addition, the more compact body and narrower milling width of medium-sized milling machines compared to large ones can also avoid the potential risks brought about by pad construction.