Technical paper bbr - Fachmagazin für Brunnen- und Leitungsbau (Professional journal for well and pipe construction) IFAT 2012 Edition

Transcription

1 Technical paper bbr - Fachmagazin für Brunnen- und Leitungsbau (Professional journal for well and pipe construction) IFAT 2012 Edition Premiere of Alphaliner 1500 in Hamburg Fast and cost-effective rehabilitation for wall thicknesses over 10 millimetres with pure UV-light curing. The new Alphaliner 1500 liner type developed by RELINEEUROPE based on the Alphaliner 1200 was deployed in a rehabilitation project in Hamburg for the first time on 1 November Hamburg's drainage company Hamburger Stadtentwässerung (HSE) had put the renewal of mixed water-sluices in the district of Blankenese out to tender. A TV examination had revealed significant damage in the drainage pipes constructed in In addition to corrosive damage, broken parts, positional damage, encrustation and deposits were ascertained both in the floor as well as in the lateral protruding into the pipes. The overall rehabilitation activity was divided into two sections. In the Baurs Park area, a residential area partially inaccessible with heavy equipment and which has a park, approximately 590 metres of mixed water-sluices with small diameter DN200 and DN250 were to be rehabilitated. In the second section in Mühlenberger Weg, an egg-shaped section 369 metres long overall of the Dimension 900/600 had to be renewed. Due to the damage formed and as the sluice floor was at a depth of up to 5.65 metres, a composite wall thickness of 11.4 millimetres as required statically was calculated for the GRP slip liner. Stefan Jensen, managing partner at the pipe-rehabilitation company Jensen from Bordesholm which was commissioned with carrying out the rehabilitation, suggested that the client rehabilitate one of three sections of the egg-shaped section in Mühlenberger Weg with the Alphaliner 1500 from RELINEEUROPE. As it is standard when pre-qualifying new technologies, HSE agreed to this on condition that this construction area is inspected and documented precisely by its building project manager Torsten Helms using a detailed Page 1 of 11

2 checklist. Jensen rehabilitated both the other 139 and 89 meter sections with the Alphaliner 1200 system with combined curing. This allowed both systems to be compared in practice under virtually identical working conditions. A new light source with a capacity of 12 x 1,000 Watt manufactured by RELINEEUROPE as a prototype in 2011 was used for the curing. The advantages for the construction site logistics were obvious as explained by Stefan Jensen: The liners with combination curing arrived at the construction site via refrigeration logistics. The lorry had to be left stationary at night and supplied with electrical power. In contrast the new Alphaliner 1500 was able to be unloaded directly at the construction site without any additional protective measures. The technical installation procedure was identical for both types of liner. Both were pulled into the ducts using a conveyor, sealed with packers and set up with compressed air. In order to confirm the pulling speeds calculated for an egg-shaped section of the Dimension 900/600 and of this wall thickness with the Alphaliner 1500, temperature sensors were placed every five metres on the outer side of the liner set up with compressed air in order to precisely control the curing process. After the light source had travelled through 20 metres of the sluice with the speed increasing constantly it was clear that a curing speed of 60 centimetres per minute results in a safe and complete curing of the laminate. In order to still have some safety reserves the overall section upon which the new type of liner was being used was cured with a speed of 50 centimetres per minute, i.e. approximately 30 metres per hour. As a result the curing process had been completed for the 140-metre long section after around 4.5 hours. The material samples taken on site and the laboratory tests for these were accompanied and carried out by Siebert & Knipschild, Oststeinbek. The properties required were clearly overachieved. Alphaliner 1500 Profile 600/900 Sample 1 Combined curing Sample 2 UV-light curing Bending E module Bending stress Composite wall Material sample E 1 Short term thickness water-tightness Short term [MPa] [MPa] [mm] Testing time 30min; target actual target actual target actual pressure -0.5 bar tight tight Curing Speed 110 cm/min cm/min Page 2 of 11

3 If the curing speed alone had been the decisive factor in the rehabilitation then the procedure with combined curing would still have been clearly superior. This type of liner was cured on the construction site in Hamburg at 1.1 metres per minute, i.e. more than twice the speed compared with the Alphaliner Nevertheless, experienced rehabilitation expert Stefan Jensen still sees the new Alphaliner 1500 system as superior. With around 30 metres per hour the curing performance is within a very good range from an economic point of view. Furthermore, the fact that there is no need for any of the refrigeration logistics results in considerable cost savings. For wall thicknesses of up to 12 millimetres Jensen also sees a bright future for the new type of liner based on the corporate risk which is considerably lower and the increased flexibility on the construction site. This covers around 80 percent of cases where we use combined curing with peroxide support today". Page 3 of 11

4 Innovation with UV-light curing liner systems It is generally acknowledged that liners have evolved over recent years into the most important process used in the area of trenchless sewer rehabilitations. Whilst it was the smaller diameters that were rehabilitated more with the different liner processes in the early years, in recent years it is the larger sewage pipes that have become increasingly important in tenders. The quality of the liners, the extensive experience in liner production and the rehabilitation projects implemented on construction sites by trained installation crews, plus not least standardisation both in terms of standards and tenders have been crucial here in convincing planners and network operators. RELINEEUROPE AG also recognises this trend in its production figures. The demand for light curing Alphaliners in diameters above DN600 (in particular DN800) has risen sharply. Here RELINEEUROPE further developed the established Alphaliner 1200 in order to be able to offer users premium technology around the world. In addition to its known properties the Alphaliner 1500 offers improved curing for high wall thicknesses. Together with new and improved UV technology based on considerably higher UV radiation power, the Alphaliner 1500 forms an innovative system for faster, flexible and controlled curing for larger diameters over DN600 - up to DN1300 and wall thicknesses above 10 mm. Higher wall thicknesses are generally also required for the liners used depending on the static load when rehabilitating larger sewer diameters over DN600. Wall thicknesses of between 10 and 20 mm can be achieved with fibre-glass reinforced liners. Controlled, regulated and rapid curing of these liners on site imposes corresponding high requirements on the design, the installation crew and the technology used. For the different UV-light curing liners on the market the curing of wall strengths in the 7 to 10 mm range with pure UV curing is state of the art. So-called combination curing has been used for greater wall thicknesses for around ten years, i.e. where UV-light curing is supported with heat curing. For this the exothermic reaction temperature in the resin resulting from the UV-light curing is used to start up the hardeners reacting to heat (so-called peroxide). This way the laminate can be controlled over the entire wall thickness and can cure completely even with rapid pulling speeds. If the Alphaliner system is used for the rehabilitation activity then pulling speeds of approx. 50 cm/min can be used for large diameters with wall thicknesses above 10.0 mm (corresponding with approx. 30 m/hour). One disadvantage with combination curing is the logistics effort (delivery of the liner on the refrigerated container with a constant storage temperature of +10 C; short storage stability Page 4 of 11

5 of a maximum of 2 weeks), which reduces the benefit of UV-light curing to the greatest extent possible. Using adapted and efficient curing technology reduces the risk of poor curing to virtually zero. In principle GRP liners can also be securely cured with greater wall thicknesses over 10 mm using pure UV-light curing. However, the only possible pulling speeds for the UV light sources are in the 5 to 10 meter per hour range due to the very different UV curing technology with low outputs, making these very slow and therefore uneconomical. The slow curing has an immediate effect on construction site planning as in many cases the water drainage and finishing work also have to be planned totally differently, generally with increased costs. The advantages of UV-light curing, i.e. speed, project flexibility, liner storage stability and controllability over the curing are therefore of only very limited importance. Alphaliner Overall system optimisation RELINEEUROPE has further developed its existing liner system with the Alphaliner 1500 version which allows curing of liners with large diameters and high wall thicknesses required statically of over 10.0 mm with pure UV light. In order to achieve measurable progress with this it was necessary to optimise the overall system of liner material and UV curing technology with both aligned to each other exactly. There were two aims at the focus of the development: Greater transparency of the liner material and a more powerful Alphaliner UV technology. Optimised materials for the UV curing are used in the Alphaliner production independently of diameter and wall thickness, without the liner properties being limited in terms of static load or mechanical and chemical resistance. With this the translucence relates to the light spectrum in the range of approx. 400 nm used with this curing technology. In order to achieve good curing in the fastest time possible the UV light used must completely penetrate the entire wall thickness of the laminate with the highest possible radiation intensity or power density. Light absorption, diffusion and reflection in the material, as is facilitated e.g. through ingredients and additives, must be minimised for optimum liner construction. This applies in particular to high wall thicknesses. The high-tech inner film used by RELINEEUROPE which is removed from the liner after curing stands out as a composite film through its excellent properties such as high loadability and optimum light transparency. To understand this more clearly: The thicker the design of the inner film, the greater the mechanical load that it can take when the UV light chain passes through. However, it also loses transparency at the same time through this. An increase in the film strength by just 0.1 mm can quickly lead to increased light absorption of up to 10% and thereby poorer curing. The polyester resin (UP) Page 5 of 11

6 or the vinyl ester resin (VE) used in industry are also already optimised for reactivity and transparency by way of the light initiator used. With the Alphaliner 1500 there was a further successful optimisation related to the transparency of the fibre-glass complex used. In order to be able to offer additional functions the fibre-glass complex was further developed in terms of translucence based on the established Advantex ECR fibre glass from the manufacturer Owens Corning OCV Technical Fabrics. As a result the UV light is able to radiate better over the entire wall thickness of the Alphaliner 1500 or the radiation intensity decreases much more slowly through the entire wall thickness in the process. This results in improved curing, in particular for greater wall thicknesses. UV-light source optimisation RELINEEUROPE already marketed its own UV lighting with improved performance when the company was founded in This delivers up to 9 x 1,000 Watt (the outputs can be used in degrees of 100 Watt depending on the diameter). It stands out from all other existing UV systems on the market primarily through its controlled stable UV-light performance over its service life. This means that normal losses in performance are compensated through the control technology installed. In addition this new technology provides up to approx. 20 % greater radiation intensity (W/mm 2 ) compared with traditional UV technology. Using this technology it had already been possible to implement wall thicknesses of up to 12 mm with pure UV-light curing with pulling speeds of 10 to 15 m/hour. However, in order to arrive at similar curing times as are achieved with the Alphaliner combination curing times 30 m/hour), even more powerful UV radiators with up to 2,000 Watt were incorporated into the development. A light-source prototype with 12 x 1000 Watt overall (total output 12,000 Watt) has been used successfully by the pipe rehabilitation company Jensen in Bordesholm since the middle of last year. Based on the results from the construction site a UV-light source was developed by RELINEEUROPE with 6 x 2,000 Watt (12,000 Watt) light output which was developed and constructed specifically for curing large diameters and high wall thicknesses. The 6 x 2000 Watt UV-light source consists of 3 x 2 UV radiators switched on in succession. The radiation intensity measured is approx. two to three times higher than with the 1,000 Watt radiators. A further advantage with this technology is the fact that the 2,000 Watt radiators can be used in the following degrees: 1,000 W, 1,200 W, 1,500 W and 2,000 W. This enables use for the entire diameter range of DN600 to DN1500 including egg-shaped sections. (The option of combined curing still exists as was the case previously). This new UV-light source also stands out through its especially Page 6 of 11

7 compact design since installation of the light sources in the narrow ducts is very costly, particularly for large diameters. This will be presented to the interested audience at this year's IFAT Construction site and laboratory tests provided the following results or forecasts for the new UV light source technology: Results from different tests or objectives for curing performance for different UV - light-sources with installation of an Alphaliner 1500 Light sources DN/WD RELINEEUROPE 9 x 1,000 W RELINEEUROPE 12x1,000 W Prototype RELINEEUROPE 6 x 2,000W Traditional technology 8 x 1,000 W for comparison DN600/6 mm 50 m/hour m/hour) m/hour) 24 m/hour DN800/8 mm 30 m/hour m/hour) m/hour) 15 m/hour DN1000/9 mm 25 m/hour m/hour) m/hour) 10 m/hour DN1000/12 mm m/hour m/hour) m/hour) 5-7 m/hour Summary: With greater transparency for light-curing liner materials and powerful UV technology it is also possible to benefit from the major advantages of pure UV-light curing compared with traditional liner processes with the rehabilitation of large diameters with high wall thicknesses. With the Alphaliner 1500 RELINEEUROPE has developed a unique system for more rapid, flexible and controlled curing of larger diameters of DN600 to DN1300 and wall thicknesses over 10 mm. The advantages of the system with improved curing for high wall thicknesses are important when using new innovative UV technology with considerably higher UV-radiator output. A curing trial completed to ascertain the output limits provided excellent results that allow even greater potentials for optimisation to be expected for the future. As such it was possible to cure a wall thickness of 19mm purely with UV-light using a 2000 Watt radiator after 10 minutes of radiation time. This way a pulling speed in the range of 10 to 20 m/hour can be expected with the new 6 x 2,000 Watt light source and a radiation surface of 3 metres. In Page 7 of 11

8 parallel with this test the 1,000 Watt radiator was only able to cure 13 mm in this period. Future developments can be expected! Authors: Christian Noll, Member of the RELINEEUROPE AG Board Benedikt Stentrup, Managing Director of RELINEEUROPE Liner GmbH&Co.KG Stefan Reichel, Managing Director of RELINEEUROPE Liner GmbH&Co.KG RELINEEUROPE Liner GmbH&Co.KG Große Ahlmühle 31 D Rohrbach Page 8 of 11

9 ALPHALINER production breakdown in % DN300 >DN300 DN500 >DN500 DN800 >DN800 DN % 23% 18% 12% 6% Image: RELINEEUROPE figures: Disproportionate demand for light curing Alphaliner over DN800 Schematic drawing Image: OCV Owens Corning Composite Material: ECR fibre glass with transparency improved considerably for excellent UV light curing Page 9 of 11

10 Image: Prototype: RELINEEUROPE Light source dual core 12 x 1000 W Section: 1 site: 3m Temperature in C Cable 1 Cable 2 Cable 3 Cable 4 Time of measurement Image: RELINEEUROPE Curing test: Reaction temperature sequence with UV light curing of a DN1000/12.8 mm wall thickness Page 10 of 11

11 Output (%) UV curing systems Conventional curing systems Time t (h) Image: RELINEEUROPE radiation performance: Stability over the passage of time Page 11 of 11