Narrow streets and the typical big-city traffic in the Belgian capital city of Brussels were a major challenge for the installation of the large and heavy iMPREGLiners, to be installed within the narrow and excessively high egg shape-profile sewer pipes in the Schaerbeek district. In addition the access points were very narrow for those large and heavy liners and the curvy host pipes required very experienced planning as well as execution on site.
A camera inspection that was commissioned showed intense damage to the host pipe at the 43 m, 49 m and 45 m locations, incl. missing entire pipe sections. The Kumpen company won the tender with the most cost-effective bid. Kumpen is a renowned and experienced construction company with approx. 300 employees and its registered office in Hasselt, Belgium. In addition to a long experience in civil engineering and road construction, Kumpen also has extensive experience in trenchless pipe rehabilitation.
The subject matter of the bid for the rehabilitation in Brussels was the lining of the deteriorated host pipe with the iMPREGLiner GL13 and curing it by using high-tech UV technology. Furthermore, Kumpen took over the entire preparation process, such as high-pressuring flushing of the bracket and the removal of loose wall sections and filling of the voids by hand.
The size of the iMPREGLiner for the special profile was calculated at 3,420 mm (a round equivalent of DN 1088). For the determination of the required wall thickness for this type of pipe profile, many parameters had to be considered. A standard calculation for such pipe profile is not possible. Due to the high material properties of the liner, a wall thickness of only 17.9 mm was determined.
The iMPREGLiner GL13 material properties with its significant long-term e-module of 14,900 N/mm² allowed such favourable wall thickness, resulting in a minimal diameter restriction for max. flow and hydraulics due to the very smooth surface generated when applying the UV curing technology.
The GFK hose liner and curing process using UV technology is presently the most cost-effective, cleanest and fastest rehabilitation process on the market. Even under the dense conditions in inner city areas or in high-traffic environments, rehabilitation is easily possible, since only a small amount of equipment is required on site.
The process is extremely resource / environmentally friendly, in comparison to the conventional rehabilitation processes using hot water or steam cure. Due to the limited equipment needed and the low energy demand curing method, the carbon footprint in comparison to other rehabilitation processes is extremely small.
Kumpen has its own, state-of-the-art UV curing rig and a well experienced rehabilitation team. To support this special project, an experienced applications engineer from iMPREG was also on site. Furthermore, a transport conveyor belt with an automatic folding unit was leased out by iMPREG, which made the insertion of the liner into the old pipe much easier.
The iMPREGLiners that were installed had a weight of 130 kg per linear meter, which led to weights of 5.6 tons, 6.3 tons and 5.9 tons for the individual liners. The handling alone of such large and heavy liners requires a great deal of experience and know-how. Same applies for the other work in the compact access points, such as closing the ends of the liners with so-called packers and the insertion of the light source.
The liner was cured using a UV double core with 8 x 1000 W. The core was aligned to the shape of the special profile pipes. The pull speed curing the liners was adapted for optimum curing of the liners. Special egg shape profile packers were used with a size of 1200 x 800 mm, as they adapted best to the shape of the special profile. This was important so the liner had a tight fit to the host pipe. The curing took place with a pull speed of 0.25 – 0.3 m / minute.
The rehabilitation was completed in only three consecutive working days and the sewer network was recommissioned. The laterals were able to be reopened immediately after the curing process and were opened and re-connected by the Kumpen team using epoxy material.
The client was highly satisfied with the high-quality result of the rehabilitation project and the quality of the materials and work conducted. The preparation and cooperation between the experienced Kumpen team and the iMPREG Group, resulted in a high quality and satisfying project.
The rehabilitation works in Brussels will already continue for Kumpen in September 2016.