Revaluation of Wastewater System in Bratislava with GRP Pipes

The Water Company of Bratislava, who was in charge of finding the optimal solution to the results of revaluation, decided to reconstruct and to extend the existing waste water system. They proposed to have the old DN 2600/1650 concrete pipeline cleaned and recommended its rehabilitation with HOBAS® CC-GRP SewerLine® Systems DN 1400. HOBAS products were chosen due to their hydraulic performance, the proven leak tightness of the system and the relatively low weight of even large profiles. In order to extend the network’s capacity, the Water Company of Bratislava decided to build a second line running along the same route and functioning as twin system. Calculations by the project team showed that HOBAS® CC-GRP Pipes DN 2000 would ideally fulfill future demands. Due to the limited space on site the installation was realized trenchless and in tunnels of 1.3 km length. Steel frames were used in these tunnels and as a first step steel host pipes DN 2300 were installed into which HOBAS® CC-GRP Pipes DN 2000 were consequently inserted. The tunnels were prepared with non-mechanized and semi-mechanized drill heads as well as by classic mining. The length of the drilling sections were between 100 and 145 m. As next step, the gap between the host pipe and CC-GRP Pipe was grouted with suitable materials.