Applications Of PU Grouts
In the recent years, PU grouting technologies have expanded substantially from the mining applications to civil engineering. Currently, PU injection grouts are employed mainly in the fields such as underground constructions, tunnel, stabilization of loose material in the foreland of excavation, securing of excavation during tunnel construction, preventive improvement of mechanical properties of the rock mass, sealing and stopping of water inflows into the construction, anchoring of soil and rocks and stabilization of the surroundings of the mines. The key advantage of PU grout is that it is water activated where as most of the other grout materials require the elimination of water intrusion before the grouting is started. The cured grout is designed to accept structural movements and hence PU is efficacious in strengthening the structures which are subject to contraction or expansion as well as movements due to seismic activities while rigid materials like cementitious and epoxy grouts are prone to failures. Many below-grade structures are customarily treated with liquid applied membranes that are applied on the positive side as waterproofing. With the polyurethane injection grout systems, this costly step can be evaded. A series of holes are drilled through the structure from the negative side and the resin is injected to create a water impenetrable barrier between the backside of a structure and the soil matrix from the negative side and stabilizing soils.