Jet grouting produces cylindrical body made up of a mixture of grout and soil particles in the ground , which have improved characteristics compared to the native soil. It completely breaks the structure of the soil, and the particles are mixed with a binder, an we get homogenized mass with improved properties.
The technology is used in various types of soil with different grout :
- water- cement mixtures
- water- cement - bentonite mixture
- lime (pure lime , lime with cement , etc.) - in special cases
- Used extremely high pressures : 30-70 MPa .
Fluid is injected into the ground speed of 250-330 m / s and the high speed of the fluid used to break up ( cutting ) the structure of the soil , moving particles and their mixing with cement mortar
There are three main methods of performance jet grouting :
- Singlefluid system ( injection mixture )
- two-fluid system ( mixture - air or a mixture - water )
- trofluidni system ( mixture - water - air )
Performing injection of the 2 - fluid system achieves nearly twice the diameter of the cylinder 1 in relation to the fluid , and a 3 - fluid system it is approximately 3 times the diameter of the cylinder 1 with the built - fluid system , but only 50 % in relation to the performance of the 2 - fluid circuit .
Consumption of cement increases with the volume of the injected body but its share in a mixture of cement - soil particles fall . This is partly explained by a certain decline in the strength of the soil mass injected at work with more fluid compared to one .
The price of equipment to work with a much more fluid increases , which significantly affects the price of the final product .