@inproceedings{HerzSigruenerMuscatetal.2023, author = {Herz, Jonas and Sigr{\"u}ner, Michael and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Co-extruded polymer fibers for concrete reinforcement}, series = {Proceedings of the 37th International Conference of the Polymer Processing Society (PPS-37)}, volume = {2884}, booktitle = {Proceedings of the 37th International Conference of the Polymer Processing Society (PPS-37)}, number = {1}, doi = {10.1063/5.0168511}, year = {2023}, abstract = {Corrosion of steel reinforcements in concrete constructions is a big topic for the building industry. Polymeric materials are a possible alternative due to their ability to withstand corrosion. To replace steel reinforcements, fibers with high mechanical properties and a good bonding ability between fiber and concrete are needed. Today different approaches for concrete reinforcement by polymer fibers have been investigated. The bonding ability of the fibers can be increased by mechanical anchoring, e.g. crimped or embossed fibers, as well as by a chemical bonding between concrete and fiber surface. To realize the requirements of high mechanical properties and a good bonding behavior, a fiber that is drawn from a co-extruded filament shall be produced and tested. The filament owns an innovative core-shell-structure. The core maintains the fiber-stiffness and the tensile strength while the shell allows using another material to affect the bonding behavior of the fiber. This study shows the usage of fibers with differing shell materials to examine their influence on the mechanical properties of the fiber in total and the adhesion abilities to concrete. As core material, an unfilled polypropylene (PP) is used. The shell materials are varied using different polymers e.g. polypropylene or ethylene acrylic acid copolymer, as well as two PP based compounds filled with wood particles and calcium carbonate blended with a maleic anhydride based coupling agent. The mechanical properties of the fibers are tested by fiber tensile tests to compare the younǵs modulus and the tensile strength. The influence of the shell phase on the bonding ability to concrete is evaluated by the interfacial shear strength calculated from single fiber pull-out tests. Microscopy is used to interpret changes before and after pull-out. The results depict incredible positive effects and allow new insights in possible materials for fiber reinforced concrete constructions.}, language = {en} } @article{HerzMuscatStruebbe2025, author = {Herz, Jonas and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {The Influence of Fillers on the Reinforcement Capabilities of Polypropylene Based Mono-Material and Core-Shell Fibers in Concrete, a Comparison}, series = {Polymers}, volume = {17}, journal = {Polymers}, number = {13}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/polym17131781}, pages = {24}, year = {2025}, abstract = {Noncorrosive concrete reinforcement, such as polymer fibers, is needed to overcome the current issues caused by corroded steel reinforcements. Fibers made of polypropylene show a low bonding behavior in concrete. Fillers can help to overcome this issue but often lead to reduced mechanical properties. Core-shell fibers, which split the mechanical properties and the bonding behavior between the core and the shell component, could be a solution. This study investigates mono-material and core-shell fibers produced with calcium carbonate and bentonite fillers and compares their behavior in tensile tests, density measurements, contact angle measurements, topography measurements, single fiber pull-out tests, reflected light microscopy, and thermogravimetric analysis. The fillers caused an increased drawability, resulting in higher mechanical properties. Further, in the core-shell fibers, the calcium carbonate increased the surface roughness, which led to a better anchoring of the fiber in concrete, which was also visible in the deformation during pull-out observed in reflected light microscopy pictures. The thermogravimetric analysis showed a delay in onset of degradation for fibers containing bentonite.}, language = {en} } @misc{StruebbeMuscatZenz2023, author = {Str{\"u}bbe, Nicole and Muscat, Dirk and Zenz, Vitus}, title = {DEVICE FOR THE PRODUCTION OF BIOPOLYMERS FROM BIOMASS (EP4130532A1)}, editor = {European Patent Office,}, year = {2023}, abstract = {Pressure lock (10), extruding apparatus (50) for high pressure extrusion, process for producing biopolymers from biomass and use of the extruding apparatus for a process for producing biopolymers from biomass allowing continuous operation of a high pressure process.}, language = {en} } @inproceedings{SigruenerMuscatStruebbe2021, author = {Sigr{\"u}ner, Michael and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Influencing the bonding ability of polypropylene fibers to concrete by blend hydrophilization and reactive functionalization}, series = {IUPAC MACRO2020+, 48th World Polymer Congress, 16. - 21. May 2021}, booktitle = {IUPAC MACRO2020+, 48th World Polymer Congress, 16. - 21. May 2021}, year = {2021}, language = {en} } @misc{HerzHefenbrockLorenzetal.2024, author = {Herz, Jonas and Hefenbrock, Sophia and Lorenz, Katharina and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Polyketone-Polypropylene Core-Shell Fibers for Concrete Reinforcement}, series = {Proceedings of the 39th International Conference of the Polymer Processing Society (PPS-39)}, journal = {Proceedings of the 39th International Conference of the Polymer Processing Society (PPS-39)}, editor = {Ediciones Uniandes,}, doi = {10.51573/Andes.PPS39.GS.FF.1}, pages = {167 -- 177}, year = {2024}, abstract = {Corrosion of the commonly used steel reinforcements weakens the structural strength of concrete. To oppose this issue, concrete reinforcements in the form of polymer fibers are investigated. These polymer fibers need a good bonding ability to concrete and good mechanical properties. This study investigates core-shell fibers produced from polyketone and polypropylene mixed with a compatibilizer. The core-shell fibers were produced by coextrusion and drawing. The fibers were analyzed by tensile tests, a single fiber pull-out test, contact angle measurements, scanning electron microscopy and thermogravimetric analysis.}, language = {en} } @article{SigruenerMuscatStruebbe2021, author = {Sigr{\"u}ner, Michael and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Investigation on pull-out behavior and interface critical parameters of polymer fibers embedded in concrete and their correlation with particular fiber properties}, series = {Journal of Applied Polymer Science}, volume = {138}, journal = {Journal of Applied Polymer Science}, number = {28}, pages = {50745}, year = {2021}, abstract = {A crucial problem in concrete engineering is the corrosion of steel reinforcements. Polymer fibers as alternative reinforcement material can prevent corrosion; however, high adhesion to concrete and good fiber mechanics are necessary for polymers to be considered as an alternative reinforcement. This study tested different thermoplastic polymer materials to evaluate their level of adhesion to concrete. The adhesion properties of different self-drawn polymer fibers were analyzed by extracting the fibers from concrete using single fiber pull-out test (SFPT). To determine the adhesion mechanism, different polymer properties were analyzed and correlated to SFPT. Strong evidence was found that the fibers mechanical properties correlate with SFPT. Roughening the fiber surface increases the SFPT results significantly. While highly polar materials can support the adhesion process, a clear correlation could not be found. This study identifies high stiffness and roughness as the crucial properties of polymer fibers used in concrete engineering. If these factors can be engineered into the fiber, polymer fibers can present an alternative to steel in concrete reinforcement.}, language = {en} } @inproceedings{ZenzMuscatStruebbe2023, author = {Zenz, Vitus and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Development of a new granulate feeding system for gas pressurized extrusion processes}, series = {ANTEC 2023}, booktitle = {ANTEC 2023}, publisher = {SPE ANTEC}, year = {2023}, abstract = {One major problem of a continuous process like plastic extrusion is their incapability to deal with non-local gas pressure. This is an inherent problem because a continuous process has an open end in the feeding port where pressure can escape. In this study a novel feeding system was developed to enable granulate feeding into gas pressurized processes inside a single- or twin-screw extruder. With this apparatus gas pressure can be applied inside the extrusion process. The apparatus separates the pressurized extruder from the dosing equipment that feeds the extruder. It keeps the pressure inside the system while continuously feeding new material into the process. A small-scale prototype was designed for proof-of concept. The small size of the prototype was able to handle small amounts of granulates of around 100 - 200 g/h. An applied gas pressure of 8 bar was achieved. In future optimizations, throughput can be increased and maximum applied gas pressure towards 15-20 bar.}, language = {en} } @article{ZenzMuscatStruebbe2023, author = {Zenz, Vitus and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {So wird Bernsteins{\"a}ure aus Holzreststoffen gewonnen}, series = {Plastverarbeiter}, volume = {2023}, journal = {Plastverarbeiter}, number = {04}, publisher = {H{\"u}thig GmbH}, address = {Heidelberg}, pages = {22 -- 25}, year = {2023}, abstract = {Die effiziente Umwandlung von lignocellulosehaltiger Biomasse wie Restholz ist eine wissenschaftliche sowie technologische Herausforderung weltweit. Die Technische Hochschule Rosenheim entwickelt gemeinsam mit Partnern ein neues Verfahren zur Herstellung von Bernsteins{\"a}ure aus Holzreststoffen.}, language = {de} } @inproceedings{HerzSigruenerKrekemeyeretal.2021, author = {Herz, Jonas and Sigr{\"u}ner, Michael and Krekemeyer, Markus and Kazmi, Monis and Schuster, Jens and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {INVESTIGATION OF AN INNOVATIVE WOOD-PLASTIC HYBRID LAID FABRIC FOR THE REPLACEMENT OF STEEL REINFORCEMENTS IN CONSTRUCTIONS}, series = {SAMPE Europe 2021 Conference, Baden/Z{\"u}rich, 29. - 30. Sept. 2021}, booktitle = {SAMPE Europe 2021 Conference, Baden/Z{\"u}rich, 29. - 30. Sept. 2021}, year = {2021}, language = {en} } @inproceedings{HerzSigruenerWalteretal.2022, author = {Herz, Jonas and Sigr{\"u}ner, Michael and Walter, David and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Coextruded Polymeric Bicomponent Fibers for Concrete Reinforcements}, series = {SAMPE Europe Conference Proceedings 2022, Hamburg, 15. - 17. Nov. 2022}, booktitle = {SAMPE Europe Conference Proceedings 2022, Hamburg, 15. - 17. Nov. 2022}, year = {2022}, language = {en} }