@inproceedings{HerzLorenzMuscatetal.2024, author = {Herz, Jonas and Lorenz, Katharina and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Polymeric core-shell and mono-material fibers for concrete reinforcement}, series = {AIP Conference Proceedings}, volume = {3158}, booktitle = {AIP Conference Proceedings}, number = {1}, organization = {38th International Conference of the Polymer Processing Society (PPS-38)}, doi = {10.1063/5.0204946}, year = {2024}, abstract = {A reinforcement of concrete structures is needed because of the low tensile strength of concrete. Corrosion of the usually used steel reinforcments cause issues during time. Therfore, alternative reinforcements produced from non-corosive materials - like polymer fibers - become more interesting. A polymer fiber has to reach high mechanical properties and a good bonding ability to concrete. Both properties can be influenced by the selection of polymer and the used production process. Two polymers, polypropylene and aliphatic polyketone are tested within this study. First mono-material fibers of each material are produced and tested, later the materials are combined in a core-shell fiber. All fibers are produced by standard extrusion or coextrusion and a later drawing process. The mechanical properties are determined by tensile tests. The calculation of interfacial shear strength from single fiber pull-out tests allows an evaluation of the bonding ability. Additionally, fiber surface before and after pull-out is examined using reflected light microscopy. Contact angle measurements are done to evaluate possible influences of the surface energy and polarity. Density measurements are used to compare weight potential of the different mono-material and core-shell fibers. The results show good mechanical properties for all fiber materials. The interfacial shear strength is ≈ 2-3 times higher for fibers with polyketone compared to the ones with polypropylene at the fibers surface, which can be explained by higher surface energy and polarity of the polyketone compared to polypropylene and different surface deformation during pull-out. Lower densities are reached by fibers containing polypropylene.}, language = {en} } @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} } @inproceedings{SchusserSigruenerBogneretal.2023, author = {Schusser, Verena and Sigr{\"u}ner, Michael and Bogner, Stefan and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Effect of Fillers on the Mechanical Properties of Drawn Polypropylene Fibers}, series = {International Conference on Composite Materials Belfast 2023 (ICCM 23), 30 July - 4 August 2023}, booktitle = {International Conference on Composite Materials Belfast 2023 (ICCM 23), 30 July - 4 August 2023}, year = {2023}, 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} } @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} } @inproceedings{SchmitzHaupertRuethingetal.2021, author = {Schmitz, Regine and Haupert, Frank and R{\"u}thing, Justus and Sigr{\"u}ner, Michael and Str{\"u}bbe, Nicole}, title = {Tribologische Charakterisierung von Polymerfasern unter Trockenreibung, Mischreibung und Hydrodynamik mittels einer optimierten Pin-on-Disc-Pr{\"u}fmethode}, series = {Tribologie und Schmierungstechnik}, volume = {68}, booktitle = {Tribologie und Schmierungstechnik}, number = {3-4}, organization = {62. Tribologie-Fachtagung 2021}, pages = {13 -- 21}, year = {2021}, abstract = {Ausgehend von der herk{\"o}mmlichen Pin-on-Disc-Pr{\"u}fmethodik wurde ein Tribologiepr{\"u}fstand hinsichtlich seiner Leistungsf{\"a}higkeit zur Fasercharakterisierung optimiert und angepasst. Die Methodik wird erl{\"a}utert und erste Anwendungen im Bereich der tribologischen Charakterisierung von Einzelfasern werden vorgestellt. Der Pr{\"u}fungsablauf zur Untersuchung der Polymerfasern, deren Durchmesser nur einige 100 µm betragen, ist so generiert, dass eine Erfassung der Daten als Funktion der Zeit im Bereich von einigen 10 µm bis zu einigen 100 µm Faserverschleiß kontinuierlich w{\"a}hrend der Messung bereits in den ersten Minuten erfolgen kann. Der Pr{\"u}fmodus startet hierbei mit Linienlast und entwickelt sich dynamisch zur Fl{\"a}chenlast durch {\"A}nderung der Auflagefl{\"a}che der Faser w{\"a}hrend der Messung. Es wird gezeigt, dass Einzelfasern hinsichtlich ihrer Reibungs- und Verschleißeigenschaften in unterschiedlichen tribologischen Systemen charakterisiert werden k{\"o}nnen. Die Abh{\"a}ngigkeit der Verschleißraten von Fasermaterial, Oberfl{\"a}chenrauheit der Gegenk{\"o}rper und Schmiermittelraten wird dargestellt.}, 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{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} } @inproceedings{SigruenerMuscatStruebbe2020, author = {Sigr{\"u}ner, Michael and Muscat, Dirk and Str{\"u}bbe, Nicole}, title = {Investigation of the Bonding Behavior of Modified Polypropylene to a Concrete Matrix by Single Fiber Pull Out Tests}, series = {SAMPE Europe Conference Proceedings 2020}, booktitle = {SAMPE Europe Conference Proceedings 2020}, year = {2020}, language = {en} }