Void filling

Geological shifts continuously lead to the formation of karst cavities, crevices and fissures. These may remain dry or offer a path for waterflows. At ground level, such zones may be prone to settlement or soil shear failure. However, underground works may also be endangered, e.g. through collapse of the rock overburden.

Products used for preventive stabilization by filling the problem zones include heavily expanding injection grouts. The most suitable solution in such cases is offered by polyurethane or silicate foam resins as well as hybrid systems, e.g. RASCOhybridHMS317. The latter is a highly cost-effective cement/polyurethane mix that allows the controlled filling of karst cavities in tunnelling or shaft sinking applications.