Fibre‐reinforced plastic (FRP) – an innovative approach to further development of rock bolt technology and the development of new outlets in tunnel and structural engineering

Fibre‐reinforced plastics, known as CFRP or GRP, are used as securing elements in the form of rock bolts or concrete reinforcement in mining and tunnel engineering, civil engineering and geotechnics. Applications according to exposure classes following Eurocode 2 in the ground, in rock and concrete, which are exposed to enhanced chemical attack by groundwater and pollutant loading, mine water flow, alkalinity of the concrete, frost and thaw conditions and de‐icing salt exposure, seawater and other moist‐warm changeover conditions, also place the highest demands on permanent chemical resistance, quite apart from the high mechanical demands on the composite material. The applications discussed here require the lowest possible elastic expansion and long‐term resistance, apart from high service loads as well as good composite behavior, slight creeping, self‐extinguishing and a series of other properties. A somewhat more precise consideration of these requirements, the state of the art and other development trends show that several products are now available that for the most part meet all of these requirements. In the medium term material and product development will facilitate quite new application possibilities like pre‐ and post‐stressing technology or combinations of primary and secondary support construction, which in technical and commercial respects will open up new perspectives in mining, but in particular also in tunnel engineering and as before in civil engineering.