A zero risk strategy for the operation of the technical infrastructure of the airport is one of the principles of Flughafen Düsseldorf GmbH. Consequently the sewer network of those areas of the apron, which will be in future dedicated to the refueling and deicing of airplanes had been upgraded, when due to a construction project organisational changes in the use of the apron had to be made. Engineering office Brenner GmbH, Hennef, developed by order of the Airport Operator a prevention concept. Key issue of this concept was the protection of manholes and pipes against corrosion. The project was successfully performed within 14 days by Abwasserservice Volkner GmbH, Siegburg.
If in future airplanes need to be refueled or deiced, the pilots will have to head for other sections of the apron as they did in the past. Since on a section of the apron a new concrete pavement had to be casted, the apron traffic had to be partly re-organized. As a result deicing will be done in another section. Therefor it was not enough to re-organize the traffic and operations. Since the deicing agents are highly alkaline, and since the residues are drained via sewer pipes to the treatment plant, the concrete pipes and shafts in the new deicing section will be exposed to extraordinary chemical attack, which will result without countermeasures into premature wear and shorter life time. In order to avoid economic and ecological risk, the Airport charged engineering office Brenner GmbH with the elaboration of a concept for preventive measures to withstand the expected chemical loading.
The concept, which was developed by the engineers experienced in airports as well as in sewer rehabilitation, was mainly based on the use of the corrosion resistant materials Epoxy and glass fibre for strengthening/protecting the structures. For the sewer pipes diameter 300 mm Epoxy resin impregnated GFR long liner system PARTLINERTM plus of resinnovation GmbH, Rülzheim was to be used. For the preventive rehabilitation of the shafts another resinnovation system was selected; a 4 mm thick coating of the shafts with Epoxy resin system resiShield LV, which was chosen due to various advantages : Epoxy resin is the best option against corrosion; mineral based coatings do not withstand the chemical attack. resiShield is a robust tested, certified, and proven solution. In spring 2013 the system was certified to be long term resistant against Biodiesel fuel, one of the most aggressive chemicals in sewer pipes. Another reason for choosing resiShield: it may be applied on wet surfaces and has an excellent bonding strength.
Thomas Neber and Horst Winzen, the experts for pipe infrastructure from the Technical Infrastructure/Planning Department and Construction, Water Management of Airport Düsseldorf GmbH claim also practical reasons for choosing resiShield: “The material variation LV (low viscosity) can be easily applied by spraying and cures fast with the right hardener. Timing is an important factor for airport operations. 17 shafts had to be treated in extremely short time windows (at night, when there is no air traffic). Every minute counts, which can be saved.”
Company Abwasserservice Volkner GmbH, Siegburg, was awarded to perform the lining and coating works of pipes and shafts, since this company was trained and skilled in the installation and application of PARTLINERTM plus and resiShield, and had also expertise in working on airports.
Thanks to the close co-operation of the consulting engineers, who ensured the site supervision at night, represented by certified sewer-rehabilitation expert Dipl.-Ing. Daniel Kettler, the material manufacturer and of course the construction company the shafts and pipes of Düsseldorf Airport were made ready to meet future challenges.