[Works report] Wirtgen WR 2000 XL helps new rural road construction

Ning County is located in Qingyang City, eastern Gansu Province, and its geomorphological features belong to the typical gully region of the Loess Plateau.

The Ninglang Golden Country Road in the area is 36 kilometers long and belongs to the outer road. The original pavement structure layer has experienced large-scale cracks and shedding, and there is a serious phenomenon of water seepage and water accumulation. Once the rainy road surface becomes muddy, it seriously affects the travel and transportation of rural residents, which has a constraint on the local economic development.

Above: broken, stagnant, muddy country road

In order to promote economic development, the local government has upgraded the rural roads. The reconstructed roads will reach the level 3 standard. The roadbed will reach 6.5 meters and the surface width will reach 5.5 meters. The design strength and service life of the road will be greatly improved.

The Wirtgen soil stabilization technology was adopted for the road upgrade. The construction process is:

1. After spreading the cement on the roadbed, the soil of the roadbed is stabilized to a depth of 20 cm by the Wirtgen WR 2000 XL soil stabilizer.

2. After that, the road roller is used for compaction and leveling, and the soil is stabilized for 5-7 days.

3. A 18 cm thick cement concrete slab is placed over the stabilized soil foundation to form a durable cement pavement.

In the new construction and reconstruction of the road, soil replacement is a common construction method to achieve a stable base layer and improve the bearing capacity of the base layer.

However, soil replacement requires multiple machines and manual cooperation to complete, high cost and long construction time, and construction projects of rural roads are often difficult to achieve due to factors such as budget.

The Wirtgen soil stabilization technology used in the road reconstruction is an alternative to soil replacement, and the effect of stabilizing the base layer is realized economically and efficiently.

Above: WR 2000 XL for soil stabilization

The Wirtgen WR 2000XL used in the project, with its powerful milling and mixing rotors, blends pre-spreaded cement binders into existing soils with insufficient capacity, with a working width of 2,000 mm, maximum working depth Up to 500mm. The resulting soil/binder mix not only has a very high compressive strength, but also has long-lasting water resistance, antifreeze properties and volume stability.

Compared with the traditional construction scheme, the Wirtgen soil stabilization technology is more efficient.

• Mechanized construction, the daily soil stabilization operation can reach 8,000 square meters, and the 36-kilometer construction project can be completed in one month, while the traditional solution takes at least two and a half months.

• In-situ mixing requires only a small amount of construction vehicles and a small amount of auxiliary materials for truck transportation, saving 30% per square meter.

• With the stability of the soil, the strength of the roadbed is greatly improved, and the useful life of the road is effectively extended.

• In addition, the transportation process also reduces the carbon dioxide emissions, which is very environmentally friendly and is an economical construction option for rural road projects.

Above: Uniformly mixed soil subgrade

According to the data of China Business Intelligence Network, the mileage of rural roads (including county roads, township roads and village roads) reached 3.78 million kilometers in 2013. Among them, the county road only accounts for less than 15%, the township and village roads account for 29% and 56% respectively, and the villages that account for 11% of the total number of built villages in the country still do not cover hardened roads. From this calculation, rural roads that still have considerable mileage need to be upgraded to hardened roads.

At the same time, a considerable proportion of the roads in the entire rural road belong to the outer roads, and the use situation is not ideal, and it needs to be upgraded and upgraded.

As a cost-effective construction method, soil stabilization construction will have broad prospects for use in the construction of new rural roads.

Soil stabilization is mainly used in road infrastructure construction, airport construction, railway road bed construction, dam area construction, industrial plant construction, etc., and the engineering area involved is relatively large. If you encounter bad soil quality, the stable thickness is also deep.

Therefore, the mechanized operation is the best choice, which allows the soil and the binder to be evenly mixed, and the construction efficiency is higher.

Above: Subgrade to complete soil stabilization

Wirtgen is the first company to engage in cold regeneration and soil stabilization and has always been a leader in this field. It includes on-site cold regeneration and soil stabilization machines including WR 250, WR 2000 XL and other models.

These devices can be used in one machine: strong milling and mixing rotors can be used to cope with harder materials such as asphalt and water-stable layers in cold recycling applications; it is easier to cope with relatively soft soil stabilization operations. Soil material.

In addition to high production volumes, advanced engine management systems significantly reduce equipment fuel consumption, significantly reducing contractor construction costs. Hydraulic all-wheel drive, four-legged full-floating system and automatic power control enable efficient machine construction even on rugged mountain roads.