Sewer rehabilitation at Zürich Airport
Brandenburger Partner arpe AG, Arisdorf, Switzerland
In June 2009, the Swiss Arpe AG handled a sewer rehabilitation with tight time constraints. The rehabilitation company installed about 340 metres of Brandenburger GFRP liner on the premises of the Zürich Airport using a trenchless method. The BLUETEC® UVA light curing process provided extremely quick installation and curing times.
The construction site in front of the cargo area at Zürich Airport
A construction site on an airport invariably poses a special challenge. For the sewer rehabilitation in the areas of the bus terminal, the cargo terminal as well as one of the airfields, the sewer rehabilitation team of Arpe AG was forced to work under tight time constraints and employing special safety measures. In order to maintain the daily operations of the airport, the rehabilitation was done at night from June 22 to 25, 2009.
The order by Unique, the airport's operating company (Flughafen Zürich AG), included the installation of 39.7 metres of DN 600 inliner in the area of a bus and train terminal, three sections of DN 300 liner with lengths of about 26, 57, and 59 metres in the cargo area, as well as two 79-metre-sections of DN 600 liner at airfield Bravo. For the rehabilitation circular-profile sewers, the company relied on light-curing inliners made of glass-fibre reinforced plastic (GFRP) by Brandenburger, combined with Brandenburger's new BLUETEC® curing technology. It excels through easy handling on-site, improved curing times, and a patented quality and curing control. The operating company has relied on light-curing liners for years
The Zürich Airport has about 125 kilometres of main collection drains and 400 kilometres of inlets and drainage lines. In 1999, the state of the sewers was assessed in a complete inspection, which was repeated in 2009. The recorded results were entered in databases serving as the planning basis for a maintenance scheme that involves continuous rehabilitation measures. Light-curing liners have been used for four years now, explains Arpe project manager Antonio Lopez. "The installation and curing times, the quality and hardness have never failed to meet our requirements." 
A damage analysis of the sections currently scheduled for rehabilitation shows fragmentation, cracks, and leaking pipe joints. The sewers in the terminal and cargo areas are 40 years old, those at the airfield area only about 20 years. "The fact that we're seeing cracks already is probably due to an increased load from take-offs and landings", says Heinz Künzler of SBU, the engineering firm contracted for the rehabilitation. Any work on the airfield has to wait until the starts and landings are finished for the day. Likewise, operations in the cargo zone cannot be interrupted. By day, there is a large volume of lorry traffic. It is therefore a great benefit if the entire rehabilitation measure can be completed in one night, Künzler explains. The tender documents had not specified the type of liner. However, a system's installation and curing times were a criterion used in the assessment of the offers. "This factor was in favour of Arpe and the Brandenburger system."The curing of 40 metres of DN 600 took only about an hour
The company based in Arisdorf near Basel has rehabilitated sewers at the Zurich Airport for two years. The current order was one of the company's first assignments using the new BLUETEC® curing system. The liners were pre-impregnated with polyester resin at the factory prior to delivery to the construction site, so there was no need to handle resins or chemicals on-site. In a very short time, the experienced team installed and cured 80 metres of liner in the first night. With the BLUETEC® curing device and its UVA light chain, the curing time for a 40-metre section of DN 600 with a wall thickness of 5.4 millimetres was only about an hour. Keeping the tight schedule therefore was no problem. "It's just great to work with the new BLUETEC® equipment", says Arpe foreman Stefan Lüdi. "I don't think there is anything better." Besides speed, he also praises the monitoring system: "You always know what the inside of the liner looks like even before it's cured. During the curing process, a log is kept detailing every metre, with data on temperature, speed, and pressure."
Immediately after curing, there was a leakage test under the supervision of the engineering firm and the client, with consistently satisfactory results. Then the inlets were cut open. "Working after 12.00 am is a little risky", Lüdi summarises. After all, it is harder to avoid errors when you're tired and working under time constraints. "It's a good thing that this technology enables us to work cleanly and quickly. We were able to complete the entire rehabilitation measure, including acceptance and setting up and cleaning up the construction site, in one night." Info: the BLUETEC® method by Brandenburger
With Brandenburger's new BLUETEC® technology for trenchless sewer rehabilitation using light-curing GFRP inliners, the UVA lamps in the light sources can be operated individually at varying power levels from 400 to 1000 Watts, depending on the sewer profile. This allows for an optimal adjustment of the curing speed to the liner profile (circular, oval, or special), taking into account the diameter and wall thickness of the pipe liner. At DN 150, curing speeds of up to 150 metres per hour are possible. Expensive and elaborate control electronics have been replaced by simpler systems. This makes the system easy to operate. In the event of failures, repairs can be performed on-site in the majority of cases. The
BLUETEC® technology relies on a patented method of quality and curing control by measuring the temperature of the exothermic curing reaction. The entire light-curing process is monitored and documented online. Key parameters like UV lamp ignition times, number and power level of lit lamps, starting and finishing times, air pressure inside the liner, curing speeds, temperature readings for the exothermic curing reaction, and the distance travelled are recorded in a log. Upon completion of the rehabilitation project, the client receives a complete machine-generated documentation of the light-curing process. Additional information:
arpe AG Kanaltechnik
Hauptstraße 171
CH-4422 Arisdorf
Telefon: +41 61 971 60 22
Telefax: +41 / 61 971 61 31
infoarpe.ch | www.arpe.ch
Brandenburger Liner GmbH & Co. KG
Taubensuhlstraße 6
D-76829 Landau
T: +49 (63 41) 51 04 – 0
F: +49 (63 41) 51 04 – 155
e-mail: info@brandenburger.de
www.brandenburger.de
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