Slot channel rehabilitation on airfields requires exclusive know-how in channel rehabilitation in compliance with the most stringent safety regulations.
Slot channel rehabilitation is gaining in importance and is still a science in itself. With the Bodenbender GmbH system solution, Swietelsky-Faber GmbH Kanalsanierung has effectively and durably rehabilitated an airport in Germany!
Slot channels are sewage or rainwater drains that are open at the top. They can be found everywhere where large areas have to be cleared of water, especially precipitation.
At airports especially, there are such large areas and correspondingly kilometre-long slotted gutter networks that must reliably perform their rainwater-draining properties. These reliable slot gutter networks are also necessary in terms of environmental protection bacause paraffin and de-icing agents must be drained via the slot gutters so that pollutants do not contaminate the environment. Accordingly, the airport has the responsibility and obligation to check the slot gutter networks for leaks at regular intervals and to completely remove them.
Basically, there are two options for removing leaks in slot channels:
- the structural replacement of the leaking slot gutters with new slot gutters using the open construction method
- the rehabilitation of the slot gutters using trenchless rehabilitation methods.
The open construction method of slot gutters is impossible on an airfield purely from an organisational point of view. Accordingly, some German airports are now resorting to trenchless rehabilitation methods, thereby considerably reducing the organisational effort. The repairs can be carried out by Swietelsky- Faber’s Sewer Rehabilitation Department with a minimum of disruption during regular airport operations or during down time.
Due to the constant air traffic, the take-offs and landings, as well as the resulting forces on the pavement and the sewer infrastructure, cracks form in the existing sewer structures, which have to be renovated gradually and continuously. The sewer networks at one of the airports, for example, will be renovated and repaired in nine construction phases until 2022, so that the tightness of the slotted channels on the airfield will continue to be ensured.
Trustworthy and responsible
In addition to these comprehensive technical requirements for slot gutter renovation, the safety aspect on airfields is also a major responsibility for the organisers.
Taking the largest airport in Germany as an example, non- transferable ID cards are required for every employee and every vehicle, and there are different security regulations for the different areas of the airport. In addition, employees must obtain an ‘airport driver’s licence’ and be familiar with the traffic rules on the tarmac. For example, an A380 and its smaller colleagues always have right of way. Suppliers must be registered in advance and are not allowed to move on the aprons without a supervisor.
The rehabilitation of slot gutters has special requirements for the material installed and the know-how of the contractor. A combination of an epoxy resin and a needle felt hose was installed on the slotted gutters renovated so far. The durability of the final product under the constantly changing load of take-offs and landings is particularly important. In order to confirm the durability, the liners that had already been installed some three years earlier were checked in summer 2017 and the tightness and durability verified. The installed consumables that passed this test came from the supplier Bodenbender GmbH. The epoxy resin Bodenbender EP (former CombiTec EP), in combination with the Bodenbender needle felt hose, are convincing due to excellent static properties and the bonding with the old pipe. The bonding is of decisive importance in slot gutter renovation as it ensures that the pipe, which is open at the top, does not back up. This means that precipitation and the associated moisture cannot freeze between the newly laid liner and the old pipe and thus
the entire system is not destroyed. This feature was tested by an independent testing laboratory in advance of the renovations and meets the issued quality requirements of the airport operators.
Unlike normal underground sewerage pipes, the actual area of application for the materials, the materials are also exposed to UV radiation from the sun. Accordingly, the resistance to UV radiation had first to be proven.
For the slot opening after the liner has fully cured, a partner company in cooperation with Swietelsky-Faber constructed a machine specially developed for this purpose, which is unique on the market and in the entire industry. The development also shows that Swietelsky-Faber is in the process of securing the market for slot gutter renovation as a know-how leader. The machine can even cope with different opening shapes of the slots and has meanwhile proven itself in practice even under the toughest conditions
