Concrete reinforcement made of steel is used on almost every construction site nowadays. However, there are also enough areas of application where this conventional reinforcement cannot or must not be used for various reasons. One example is the new COMPASS-U fusion reactor research facility of the Institute of Plasma Physics of the Czech Academy of Sciences, which is currently under construction in Prague. This reactor, called a tokamak, represents an important building block in the European research programme, the long-term goal of which is to generate the much-discussed fusion energy. The experimental facility will be used to research how new technologies can be used to confine high-temperature plasmas in a strong magnetic field.
Special reinforcement for special applications
To ensure that this magnetic field can be generated undisturbed, high demands are placed on the surrounding building structures. For example, the reinforcement of the surrounding building shell must be neither magnetic nor electrically conductive in order to prevent interference, disturbance currents and falsified measurement results. This is where our glass fibre reinforcement (GRP) FIBERNOX® V-ROD from the PohlCon brand H-BAU Technik came into play: it is permeable to magnetic fields and radio frequencies and therefore meets all specifications.
The full programme
Initial considerations were based on only using GRP reinforcements for the floor slab. However, since the metal-free alternative was convincing and recalculations of the statics were necessary anyway due to the changed framework conditions, the columns and punching shear reinforcements were also realised with glass-fibre reinforced plastic. In total, 6,000 m of FIBERNOX® V-ROD reinforcement were used in Prague by the end of 2022, as well as more than 430 double-headed bolt bars with a length of 190 mm and 80 non-metallic spacers in two-metre delivery lengths each.
100-year service life
But FIBERNOX® V-ROD also shows its special strengths in other applications: Made of special E-CR glass fibres and a highly durable vinyl ester resin, the reinforcements are permanently resistant to corrosion and alkalis, which means that their usable service life can be 100 years or more, even in challenging environments. Almost exclusively, Canadian highway bridges, some of which receive road salt for up to six months of the year, are now built with GRP reinforcement.
Suitable for sensitive infrastructure
Another advantage is the low thermal conductivity, which corresponds to about one hundredth of that of steel. This is why the technology is used, for example, in sandwich anchors for insulated walls in prefabricated construction. For Christoph Spitz, GRP product manager at PohlCon, "GRP reinforcements are problem solvers for special applications where the typical properties are advantageous or make the use of a reinforcement possible at all". For sensitive and highly demanding construction projects such as bridges, tunnels, hospitals, airports or even research facilities, GRP reinforcement is therefore increasingly the method of choice.