For applications in the geo technique some proven two component polyurethane systems are provided by Nestaan Holland. Polyurethane is used at the permeation grouting process. In that process, pouring systems are injected as a fluid (chemical grout) into the soil without disturbing the existing structure of it. The pores and cavities in soil, gravel or rock are filled with polyurethane foam (to permeate) to improve the constructive properties of the soil and stem water flows. Besides the constructive property of the grouting system, it is also possible to use the filling and penetrating capacity of foam to improve air tightness of the soil.
Constructive and stemming capacity
The ground under or next to buildings may appear to be not steady enough for new building excavations. Injecting the soil with a polyurethane system may guarantee absorption of the forces caused by the pressure of the existing buildings on the ground floor. Injection of the soil may prevent a total collapse. In old mine shafts polyurethane is used to stem water flows that are running next to the existing shafts. This prevents a dangerous leakage.
At gas wells on closed dumps, a problem with the gas extraction arises after course of time. Machines extract gas from too large diameter pipes that were originally meant only for ventilation.
False air, (oxygen) is sucked in through the soil and stabilization gravel, which causes the anaerobic process that develops the biogas, to stop.
Existing wells can be transformed by lowering smaller tubes in the big diameter tubes and partly fill the arisen cavity with PUR. The pouring system is then injected on depth of 5 -10 and 15mtrs to penetrate into the stabilization gravel, which results in higher methane % in the air that may again be used for generator purposes.