Waterproof polyester inner liner
Following the discovery of widespread decay in the concrete in the sewer network, five-meter pipe sections made by krafton© from its pultrusion profiles have been installed here during recent months. The sections are placed one behind the other in the old sewer and the remaining space filled with concrete. This process creates a waterproof polyester inner liner that will significantly prolong the old sewer system’s service life.
Products and materials constantly evolve; composite is an ideal structural engineering material, particularly when the product has to satisfy demanding criteria such as light weight in combination with strength, high resistance to corrosion and good thermal or electrical insulation properties. Designing composite structures is no more complex than designing structures made from steel, wood and other building materials.
This explains why krafton© profiles have been widely used in cooling towers for some years now.
Bridges in the Netherlands
Municipality of Lansingerland
This strong bridge has a closed bridge deck and is suitable for an axle load up to 10 tons. So the bridge is also suitable for use by agricultural vehicles, which are common here in Lansingerland.
Municipality of Goes
The krafton© 400.85 plank was used here to refurbish a drawbridge in Zeeland. The bridge deck was reinstalled with the help of Constructiebedijf Hillebrand BV.
Bridge refurbishment project
Installation of GRP bridge decking elements
When the bridge was inspected in 2012, the wooden cladding was found to be badly damaged. There were holes in the decking – a potential tripping hazard for pedestrians – and the glued joints in parts of the main girders were starting to open up as a result of lateral rain ingress.
The side elements, which were protected from above by sheet trims, were still in good condition, however the wooden bridge deck was past repair.
The refurbishment project involved installing our krafton© bridge decking elements, which are made from glass fibre-reinforced plastic (GRP) and finished with an extra coating.
The GRP planks were clamped to the girders, only the outer two rows were fastened using stainless steel screws.
In addition, weak points in the original design for bridge drainage had to be corrected. To achieve this, the side elements and the reinforcing wood were covered with an EPDM film and installed with a slight forward gradient to ensure continuous rainwater drainage and avoid pooling.
Parade ground bridge
GRP bridge decking planks, krafton® 500.40
Interaction between steel and GRP
The contractor, a company from Lower Saxony that already had extensive experience with major steel structural projects, built the bridge sections in collaboration with us. The bridge features a TÜV-certified non-slip coating that meets the R12 and R13 floor slip ratings.
Enthusiastic interest in GRP
The Alderman, dr. Hofmann, supervised the works and spoke enthusiastically about the new bridge during a seminar in Germersheim, which krafton® organised one week later.
German quality and attention to detail from the Netherlands
These bridge decking elements were produced in-house by krafton® in our own production facility in the Netherlands. Thanks to our 40-year track record and DIBt-certification for the decking, they guarantee an extremely long service life and safe use of this pedestrian and cycle bridge.
Following discussions with the customer, krafton® designed and produced a mould for on-demand production. krafton® produces the “LDE”, the star-shaped plastic (GRP) element, in quantities of several linear metres in its production facility.
Glass fibre-reinforced plastic was obviously the best material for the job: The profile is installed in a dike, surrounded by sand, water, etc. GRP is a high-strength material, the profile will not break, the material will not corrode and is resistant to chemicals.
Range of thresholds
A range of thresholds made from (GRP)
The main advantages are low weight, extreme strength, resistance to breakage and the minimal coefficient of expansion. The threshold is no less than 10 times lighter than natural stone thresholds and therefore much easier to handle during manufacture, transport, final processing and installation.
The glass fibre-reinforced plastic is almost impossible to break, dimensionally stable and stronger (in terms of tensile strength) than, for example, aluminium. The black UV-resistant coating gives the part an extremely wear-resistant finish.
These thresholds are not sensitive to moisture, have a minimal coefficient of expansion (identical to concrete) and hardly contract or swell when the temperature fluctuates.
The insulation value of the basic threshold design is very favourable. The glass fibre-reinforced threshold features hollow chambers, and the air trapped in those chambers acts as a perfect insulator.
Customer-specific GRP profile for bus manufacturer
krafton® produced a range of custom GRP profiles to allow manufacture of light but strong bus bodies, and also supplied GRP profiles for the air handling system.
References for GRP Profiles: Center Parcs Aqua Mundo
Center Parcs is known for its magnificent swimming pool complexes that make visitors believe they are on a palm beach in a sun-drenched foreign holiday resort. The dome of the subtropical Aqua Mundo swimming complex at the Het Heijderbos holiday park in Heijen was completely refurbished in the spring of 2016 because the air cushion roof had reached the end of its service life, and the existing wooden roof structure was in poor condition. Wood and moisture are hardly an ideal combination and that meant a unique opportunity for our composite profiles, even though we obviously had no upfront guarantee that the customer would take the bold step of choosing our products.
The existing main trusses, made from laminated wood girders, could be retained, the rest was replaced by maintenance-free composite. This was our largest production project ever for composite I girders. The I-780x300mm girders in the bottom ring were more than 26 metres long. The vertical beams, based on the I-240x150mm profile, were more than 23 metres long. In total, more than 40 tons of composite were required.