Assembly influences on the long-term load-bearing capacity of glass/PTFE fabrics

Assembly influences on the long-term load-bearing capacity of glass/PTFE fabrics. Membrane structures are designed for a service life of between 20 and 25 years. In Germany, a combined ZiE/vBG is required for every membrane structure – whether small or large – which is based on strength and stiffness parameters that are determined on the new material depending on each individual batch. Hereby, strength-reducing influences are certainly taken into account via reduction factors, but effects from assembly are not sufficiently covered. Glass/PTFE fabrics in particular are sensitive to installation influences such as handling during transport, handling and temperature during the laying of the fabric and weathering, so that long-term damages in form of cracks in glass/PTFE membrane structures might occur, which (can) result in premature replacement of the entire covering. Investigations into the influence of weathering in combination with handling/installation-related creases in glass/PTFE fabrics have shown that certain types of creases in glass/PTFE fabrics must be avoided, while others do not (necessarily) have a detrimental effect on the long-term load-bearing capacity of the fabric itself. This contribution provides an overview of the current state of knowledge on the influence of weathering and creases on the long-term load-bearing capacity of glass/PTFE fabrics as well as recommendations for the correct installation of such membrane structures in order to avoid long-term damages. © 2024, Ernst und Sohn. All rights reserved.