TY - CHAP A1 - Mittermayr, Florian A1 - Thumann, Maria A1 - Baldermann, Andre A1 - Lindlar, Benedikt A1 - Stenger, Christian A1 - Huber, Helmut A1 - Bauer, Eric A1 - Scheutz, Rudolf A1 - Kusterle, Wolfgang T1 - Instandsetzung Bosruck-Eisenbahntunnel:Entwicklung von Spritzbeton mit erhöhtem Widerstand gegen Thaumasit-Sulfatangriff T2 - Spritzbeton-Tagung 2018. Alpbach, Tirol, 11. und 12. Januar 2018. Tagungsbeiträge. CD-ROM N2 - Im Bosruck-Eisenbahntunnel kam es in Folge v on intensivem Sulfatangriff durch Thaumasitbildungen zu erheblichen Betonschäden. Bisher sieht das Regelwerk (ÖNORM B 4710-1 und ÖVBB-RL Spritzbeton) bei Sulfatangriff den Einsatz von C 3A-freien Bindemitteln vor – dies gilt auch für Spritzbeton. Untersuchungen haben gezeigt, dass C 3A-freier Zement keinen wesentlich verbesserten Widerstand gegen den Thaumasit-Sulfatangriff aufweist. Im Zuge der Tunnelinstandsetzung war es das vorrangige Ziel, Spritzbeton mit erhöhtem Widerstand gegen Thaumasit-Sulfatangriff und ausreichender Frühfestigkeit zu entwickeln. In diesem Beitrag werden neu entwickelte Mischungsansätze und deren Umsetzung im Labormaßstab vorgestellt. Die mechanischen Kennwerte dieser Rezeptur (z.B. Frühfestigkeitsentwicklung) sowie die Ergebnisse der Dauerhaftigkeitsuntersuchungen zeigen, dass eine Rezeptur mit optimiertem Bindemittelgehalt die hohen Anforderungen im Tunnel erfüllen kann. Die Erfahrungen aus der praktischen Umsetzung im Zuge der Instandsetzungsarbeiten des Bosruck-Eisenbahntunnels im Jahre 2016 waren positiv. T2 - REPAIR OF THE BOSRUCK RAILROAD TUNNEL: DEVELOPMENT OF SPRAYED CONCRETE WITH INCREASED DURABILITY AGAINST THAUMASITE SULFATE ATTACK Y1 - 2018 UR - http://spritzbeton-tagung.com/downloads/vortraege/2018/13_Mittermayr_et_al_Spritzbeton_mit_erhoehtem_Widerstand_gegen_Thaumasit-Sulfatangriff.pdf CY - Oberperfuss ER - TY - CHAP A1 - Stauffacher, Anina A1 - Galan, Isabel A1 - Juilland, Patrick A1 - Thumann, Maria A1 - Stenger, Christian A1 - Baldermann, Andre A1 - Mittermayr, Florian A1 - Lindlar, Benedikt A1 - Kusterle, Wolfgang ED - Kusterle, Wolfgang T1 - Einfluss von Hüttensand und ultrafeinem Kalksteinmehl auf die Hydratation von jungem Spritzbeton T2 - Spritzbeton-Tagung 2018, Alpbach, Tirol, 11. und 12. Januar 2018. Tagungsbeiträge. CD-ROM KW - Spritzbeton KW - Feuchtigkeit KW - Hydratation Y1 - 2018 CY - Oberperfuss ER - TY - CHAP A1 - Juhart, Joachim A1 - Briendl, Lukas G. A1 - Mittermayr, Florian A1 - Thumann, Maria A1 - Röck, Rudolf A1 - Kusterle, Wolfgang T1 - Optimierte Eigenschaften von Spritzbeton durch kombinierte Zusatzstoffe T2 - Tagungs-CD der Spritzbeton-Tagung 2018, 11.-12. Januar 2018, Alpbach, Tirol, CD-ROM Y1 - 2018 ER - TY - JOUR A1 - Steindl, Florian R. A1 - Mittermayr, Florian A1 - Sakoparnig, Marlene A1 - Juhart, Joachim A1 - Briendl, Lukas G. A1 - Lindlar, Benedikt A1 - Ukrainczyk, Neven A1 - Dietzel, Martin A1 - Kusterle, Wolfgang A1 - Galan, Isabel T1 - On the porosity of low-clinker shotcrete and accelerated pastes JF - Construction and Building Materials N2 - Although the number and size of interconnected pores have been identified as the most important aspects of concrete microstructure, comprehensive datasets on shotcrete porosity and pore size distributions are still scarce and their key controls are poorly investigated. In this study we investigate the effects of the spraying process, setting accelerator addition and mix design on the microstructure of real-scale dry- and wet-mix shotcrete and hand-mixed and sprayed accelerated pastes. A newly proposed deconvolution analysis of the pore size distributions, measured by mercury intrusion porosimetry, offers increased precision in determining the critical and median pore diameter parameters. In total >50 samples were analysed. Results show that the dry-mix shotcrete exhibits a shift towards coarser pore sizes (∼100–1 μm) than wet-mix shotcrete. Combinations of different supplementary cementitious materials are favourable for producing wet-mix shotcretes with refined pore structures. The addition of setting accelerators, up to 10 wt-% of binder mass, and the spraying process cause systematic variations in the pore volume and pore structure of (sprayed) paste and shotcrete. KW - Porosity KW - Shotcrete KW - Mercury Intrusion KW - Durability KW - SCMs Y1 - 2023 U6 - https://doi.org/10.1016/j.conbuildmat.2023.130461 SN - 0950-0618 VL - 368 PB - Elsevier CY - 14 ER - TY - CHAP A1 - Thumann, Maria A1 - Juhart, Joachim A1 - Röck, Rudolf A1 - Saxer, Andreas A1 - Galan, Isabel A1 - Mittermayr, Florian A1 - Kusterle, Wolfgang T1 - Entwicklung neuer, dauerhafter und nachhaltiger Spritzbetone T2 - Kolloquium Forschung & Entwicklung für Zement und Beton 2018 Y1 - 2018 UR - https://zement.at/downloads/downloads_2018/Kolloquium_Kurzbeitraege_2018_neu.pdf SP - 65 EP - 69 ER - TY - CHAP A1 - Galan, Isabel A1 - Thumann, Maria A1 - Briendl, Lukas G. A1 - Röck, Rudolf A1 - Steindl, Florian A1 - Juhart, Joachim A1 - Mittermayr, Florian A1 - Kusterle, Wolfgang ED - Beck, Thomas ED - Myren, Synnøve A. ED - Engen, Siri T1 - From Lab Scale Spraying to Real Scale Shotcreting and back to the Lab T2 - 8th International Symposium on Sprayed Concrete : Modern Use of Wet Mix Sprayed Concrete for Underground Support, Trondheim, Norwegen. - 11. - 14.06.2018 N2 - Before new mixes are sprayed in real scale applications, lab experiments have to be carried out to provide a basis for predicting a good performance in real scale. In many cases, to understand the correlations between the behavior in the lab and in real scale spraying, a further set of experiments after the real spraying is required. In this paper we present such a two way process for two new wet mixes, one with a very low tricalcium aluminate Portland cement and the other one with a CEM I with addition of ultra-fine calcite. Calorimetry and Shear-Modulus measurements were used in the lab to monitor hydration evolution. In the real scale spraying compressive strength was measured at periodic intervals up to 24 hours. The hydration of the sprayed samples was stopped at 3, 6 and 24 hours and samples were scanned with X-ray for the identification and quantification of the phases present. The results presented are used to discuss the extent to which lab experiments can predict the behavior of mixes in real scale and how small changes in the raw materials and the mixes can lead to quite different results. Y1 - 2018 UR - https://betong.net/wp-content/uploads/8th-Sprayed-Concrete_Web-Proceedings.pdf SN - 978-82-8208-060-6 SP - 139 EP - 153 ER - TY - CHAP A1 - Mittermayr, Florian A1 - Galan, Isabel A1 - Saade, Marcella Ruschi Mendes A1 - Saxer, Andreas A1 - Kusterle, Wolfgang T1 - "ASSpC" Shotcrete research for the needs of tomorrow T2 - ICCC 2019: 15th International Congress on the Chemistry of Cement, ICCC 2019, 16.-20.09.2019, Prague, Czech Republik N2 - Shotcrete or sprayed concrete in tunneling in connection with the "New Austrian Tunneling Method” has been developed over the last decades to reach a high quality standard. However, at present the development of new shotcrete mixes is required to fulfill durability and stainability requirements, i.e. for superior performance in aggressive environments and reduction of maintenance costs. In the course of the project ASSpC ("Advanced and sustainable sprayed concrete") the research team focuses on producing and testing new and innovative shotcrete mixes using local and environmentally friendly raw materials. Sustainable and durable shotcrete with optimized mechanical and physical properties and improved chemical resistance is developed. This paper outlines the motivation for the project, gives an overview of the project structure and introduces key reaction mechanisms and environmental controls causing damage of shotcrete in tunnels. Y1 - 2019 UR - https://iccc-online.org/fileadmin/gruppen/iccc/proceedings/ICCC15_2019.pdf SP - 3518 EP - 3872 ER -