picture of structural profiles

3 March, 2020

Test: Outstanding results after 20 years inside of moist cooling tower

Together with our customer, we have tested a practiced aged GRP profile from a cooling tower with 20 years of operation, to experience what we already knew – our profiles have unique durability. With this test we can now document a longer life expectancy of the construction. For our customer, a recognized German cooling tower producer, it is of vital importance to document that the materials they choose are reliable too.

The test

A square tube with the cross-section 100 x100 x 8 mm from a cooling tower built in 1999 by the German company E&S Planbau GmbH was extracted for extensive testing and evaluations on the ageing behaviour of the material. The environment that the profile was in comprised of elevated temperatures, permanent humidity and process water. In addition, the profile was subjected to constant load for 20 years.

IMA Dresden extracted specimens for analysis and performed the tests. Prof. Dr. Jens Ridzewski, who has over 30 years of experience with fibre-reinforced polymers, undertook the evaluation and expert opinion.

Prof. Dr. Jens Ridzewski, IMA Dresden and Composite Consulting Prof. Ridzewski, about the importance of this test:
“When new products hit the market, it is extremely important to create trust and take concerns away from the customers. What Fiberline has done here is to investigate the properties of real-life ageing profiles to determine the effects of environmental impacts. Since the product is not covered by harmonized standards, the test is of utmost importance to the entire industry. I would like to see more manufacturers and operators initiate such investigations. This is a valuable contribution to increasing the safety of GRP components.”

Results benefit customers

Results are showing very low degradation of the properties and according to the current knowledge, this degradation is in the range of expectation. It should be further mentioned that these degradations are captured by partial- and safety factors that are recommended by Fiberline.

The tests that are undertaken:
• Tension in transverse direction
• Compression in pultrusion direction
• Materialography (Microscopy)

Longer life expectancy and fewer repairs

With this test, we can now document a longer life expectancy of the construction. Originally, this cooling tower was designed with a life expectancy of 20 years. As a manufacturer, the positive results will mean that we are able to decrease the conservatism that has been coupled upon the material properties and partial/conversion factors.

Product Manager Mirfet Malagic says:
“This is the first time that we as a company have taken initiative and tested profiles from an existing construction. Results have positively overwhelmed us and have strengthened our belief that our products can withstand much more.”

Test from 20 year old bridge show same results

In 2015, profiles taken from our bridge in Kolding that has been providing safe crossing access over two-lane rail tracks for over 20 years was examined. The analysis was carried out by the engeering company Rambøll with the same conclusion - namely that the degradations are well below the expected levels.

To ensure that the properties of our materials are stable in all environments, we plan on conducting similar testing in more application areas where our profiles have been used. This is just one of many steps to secure and show confidence in the material.

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