Soil stabilisation technology as a kind of Bulk Earthworks has a common operating principle with the cold recycling technology “in situ”. In both cases, a road recycler is used.

The method allows you to modify and use the soil that is already at the road construction site for the construction of road base layers.

Result

stabilisation produces a frost-resistant layer of the upper or lower road base. Other base layers are usually placed on the lower one, and an asphalt concrete pavement layer on the upper one.

Quality

You can always get the quality of the road base that corresponds to the characteristics that were included in the construction project. This is true for any category of roads. There is no difference between the traditional method and soil stabilisation. The main thing is strict adherence to the technological process.

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Photo by David McElwee on Pexels

Cost

Soil stabilisation reduces road construction costs by 30-50% compared to the traditional method. In order to fully utilize the economic resource of recyclers, operators must carefully monitor their condition and correctly perform all work processes.

How Soil stabilisation Works

Road recyclers play a central role in the application of soil stabilisation technology, as well as cold recycling technology “in situ”. The main difference between the technologies is that stabilisation is used in the construction of new roads and recycling is used in the repair of existing roads and sites.

The main feature of the recycler

The main working element of the recycler is the milling and mixing drum, which is located at its base. When the recycler moves, the drum operates on the principle of a cold milling machine: it cuts and crushes the material entering it. In cold recycling, this is old asphalt concrete, in stabilisation – soil. At the same time, the drum mixes the crushed material with binders and water. Depending on the hardness of the asphalt concrete or soil being recycled, the recycler can work to a depth of up to 50 cm.

During the stabilisation process, recyclers transform the existing soil at the construction site into a road base without the need to remove or replace it. The operating principle is the same as in recycling: the machine breaks up the soil and mixes it inside a milling and mixing drum. Cement, lime and special chemical stabilising additives are added to improve the characteristics. If there is a shortage of solid fractions, crushed stone is added. The material obtained after the recycler passes and is compacted by road rollers is called soil concrete.

workers-constructing-a-road
Photo by Rookey Pain on Pexels

Equipment set

The same equipment set is required for cold recycling and soil stabilisation. A typical working group consists of a recycler, cement distributor, bitumen truck, water truck, roller and grader.

Supply of water and binders

The cement distributor drives ahead of the recycler and distributes inorganic binder, usually cement, over the road surface in the required proportions. The water truck supplies water to the recycler drum to moisten the material to the required values. Special strengthening chemical additives can be added to the water truck. A bitumen truck is needed in case of using an organic binder – bitumen emulsion. The water truck and bitumen truck are connected by hoses to the milling and mixing drum chamber of the recycler. The speed and volume of water and bitumen emulsion supply are controlled by the on-board computer of the recycler.

What is so advantageous about soil stabilisation, if compared with the classic scheme of asphalt road construction?

When constructing roads in areas with soils of low bearing capacity, there is a large consumption of crushed stone and sand. Money is spent on the purchase and delivery of bulk materials, which affects the cost of the