Soil-Mixing Machine

a machine used in loosening and crushing soil and in mixing the soil with binding (cementing) materials while the machine is moving.

The soil-mixing machine is used in the construction of improved roads and in the construction of a foundation (supporting the cover) for major highways. Currently manufactured soil-mixing machines can be built as trailers or they can be self-propelled. The main operating members of a soil-mixing machine are the turning rotors; a machine may have two, three, or four such rotors. When the machine is moving, a leading rotor grips and loosens the soil and the next rotor crushes it. If cement is used as a binder, the cement passes through a feeder and is dry-mixed with the soil by the rotors. Two bladed rotors mix the dry soil-cement mixture with water, which is fed from a tank. Bitumen or another liquid binder is pumped from a tank and mixed with the soil. The backplate of the rotor housing regulates the height of the mixture leaving the machine and also serves to precompress the mixture.

The soil-mixing machines made in the USSR have an output of up to 0.7 km/h and produce a highway strip up to 2.4 m wide and 0.25 m deep, assuming a cement content of 15–60 kg/m²and a bitumen or water consumption of 10–50 liters/m².