Press releases from RELINEEUROPE09.02.2018
Special profile challenge in France mastered
In St. Etienne, AXEO TP renovated bricked channel with a height of 1.80 m – Alphaliner1800 with a wall thickness of almost 20 mm is cured with only UV light.
There are sewers that don’t fit into any standard. This category includes the main collector in the district of Le Soleil in the French town of St. Etienne. At a height of 1.80 m, the sewer has a 70-centimetre wide vault at the top. In the sole, on the other hand, the sewer is only 50 cm wide with straight walls in the crossbar area. For this ambitious project, Daniel Walther, the managing director of the rehabilitation company AXEO TP, based in Brumath, offered a rehabilitation with the UV light-curing Alphaliner GFRP hose liner from RELINEEUROPE to the city of St. Etienne and the water and wastewater management company Stephanoise des Eaux.
Links: Left: The sewer in St. Etienne prepared for the installation of the liner. Right: The excavation pit with the built-in liner and special packer installed
Close cooperation between installation company and liner manufacturer
Close cooperation and bundling of the expertise of all partners was required for the execution of the rehabilitation in August and September. In order to determine the required wall thickness in relation to the required load-bearing capacity, they commissioned TÜV Rhineland with a finite element calculation of the special section. The GRP hose liner manufactured with a replacement circuit of DN 1400 was set to a total wall thickness of 18.2 mm with the high mechanical KPIs of the Alphaliner1800, which was specially designed for the rehabilitation of large sections. The weight of the liner for the longest of four rehabilitation sections (135 m) was 20 t. In St. Etienne, AXEO TP has installed the largest GRP hose liner in France so far – this was cured only through UV light. The liners for the three other sections of the 380-metre long section of the Rue Louis Soulier were 72, 89 and 97 m long and also had a considerable weight. “This was a difficult construction site because we were working with many civil engineering companies at the same time”, says the AXEO Managing Director. “But together with RELINEEUROPE, we have mastered this special project and thus demonstrated what is currently possible for the rehabilitation with GRP pipe liners”.
The infeed of the liner directly from the lorry via the conveyor belt
After trenching excavation pits and constructing a de-watering system of very large dimensions (800 m3), the first challenge was to move the large and heavy hose liners, which were delivered to the construction site in 2.20-metre-wide transport crates, into the sewer, which was only 50 cm wide at the base. The shafts were up to 6 m deep. Although a special conveyor belt with folding device was used, up to six people were required to fold the liner to the required width.
Special solutions developed for the construction site
EIt was also necessary to ensure that the pipe liner could be installed with air pressure up to a height of 1.80 m, thereby establishing a positive connection to the old pipe. The rehabilitation company designed a special system for this purpose. The team also had to come up with a special solution for the curing process. With the REE4000, RELINEEUROPE's most powerful UV curing system, the hose liners with a wall thickness of almost 20 mm were completely cured at a speed of 30 cm/min. The rehabilitation of the 130 m stretch was thus completed after about 7 h.
“The decisive factor for the success of this construction site was the excellent cooperation between the installation company AXEO and RELINEEUROPE and the fact that the workers had no stress during installation”, says David Veltz of RELINEEUROPE, who, together with application engineer Stephane Antoni, supported the experienced AXEO TP team under the direction of Daniel Bannier. “The Alphaliner1800 does not require peroxide despite a wall thickness of almost 20 mm. Because of its high transparency, it can be cured only through UV light. Because of this, the team was therefore able to install the liner calmly without having to fear that the material would prematurely cure as it is the case with liners with peroxide”, says Veltz as he describes the advantages of the liner material. The team worked for one day at each of the individual sites. On the second day, the liner was installed, prepared, and cured. The historic sewer canal in the St. Etienne district, where the workers of the coal mines used to live, is thus once again leak-proof and is also equipped for the coming weight burden of future tram operations.
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