TY - JOUR A1 - Testor, Markus A1 - Kusterle, Wolfgang T1 - Druckfestigkeitsentwicklung von Spritzbetonen mit alkalifreier Erstarrungsbeschleunigung JF - Zement + Beton N2 - Spritzbetone mit alkalifreier Erstarrungsbeschleunigung werden ohne alkalische Zusatzmittel (Spritz-Bindemittel mit begrenztem Alkaligehalt oder alkalifreiem Erstarrungsbeschleuniger) verarbeitet. Ein entscheidender Punkt fuer den Einsatz der alkalifreien Erstarrungsbeschleunigung ist das geunstige Auslaugverhalten, speziell hinsichtlich der Einbringung von Alkalien in Tunnelwaesser. Diese Spritzbetone zeigen bei Kontakt mit Wasser das gleiche Auslaugverhalten wie Normalbeton. Alkalihaltige Zusatzmittel fuehrten bisher bei unsachgemaesser Anwendung auch zu Veraetzungen der Haut und der Augen (bis zur Erblindung) sowie zu Reizungen der Schleimhaeute. Die arbeitshygienischen und oekologischen Nachteile klassischer alkalihaetiger Erstarrungsbeschleuniger wurden mit der neuen Technologie ueberwunden. Die Festigkeitsentwicklungen von Spritzbetonen mit alkalifreier Erstarrungsbeschleunigung weisen unterschiediche Charakteristika auf und weichen im Festigkeitsverlauf untereinander beziehungsweise gegenueber herkoemmlichen, mit alkalihaltigen Beschleunigern versehenen Spritzbetonen ab. Eine charakteristische Druckfestigkeitsentwicklung zeigen nur Spritzbetone unter Verwendung von Spritz-Bindemitteln fuer den Einsatz mit ofentrockenen Zuschlaegen beziehungsweise Spritz-Bindemittel auch mit naturfeuchten Zuschlaegen.Werden Zemente auf Basis von Portlandzementklinker mit alkalifreiem Erstarrungsbeschleuniger eingesetzt, so sind grosse Unterschiede im Festigkeitsverlauf, primaer abhaengig vom Erstarrungsbeschleunigergehalt und Wasserzement-Wert, sowohl im Trocken- als auch im Nassspritzverfahren feststellbar. KW - Alkali KW - Construction KW - Shotcrete KW - Strength of materials KW - Tunnels Y1 - 1997 SN - 0514-2946 VL - 97 IS - 3 SP - 20 EP - 25 PB - Zement und Beton Handels- und Werbeges. CY - Wien ER - TY - JOUR A1 - Testor, Markus A1 - Kusterle, Wolfgang T1 - Vergleichende Staubmessungen bei Spritzbetonarbeiten : Meßmethoden-Einflussfaktoren-Reduktionsmöglichkeiten JF - Felsbau : Fachzeitschrift für Ingenieurgeologie, Geomechanik und Tunnelbau = Rock and soil engineering Y1 - 1997 SN - 0174-6979 VL - 15 IS - 2 SP - 125 EP - 133 PB - VGE-Verlag CY - Essen ER - TY - JOUR A1 - Fleischmann, Florian A1 - Kusterle, Wolfgang T1 - Neues Rheometer zur Bestimmung der Frischbetoneigenschaften von Selbstverdichtenden Betonen. JF - Beton : die Fachzeitschrift für Bau + Technik Y1 - 2014 SN - 0005-9846 VL - 64 IS - 9 SP - 330 EP - 337 PB - Verlag Bau + Technik CY - Erkrath ER - TY - CHAP A1 - Thumann, Maria A1 - Kusterle, Wolfgang ED - Maekawa, Koichi ED - Kasuga, Akio ED - Yamazaki, Jun T1 - Enhanced durability of shotcrete – Reduced potential for precipitations T2 - Proceedings of the 11th fib International PhD Symposium in Civil Engineering. - 29.-31.08.2016, Tokyo, Japan N2 - The contact of underground water with shotcrete leads to leaching of calcium hydroxide and can increase the precipitation of calcite in the secondary drainage system of tunnels under certain conditions. Indeed precipitations in the drainage pipes lead to high maintenance costs. Within a research project the leaching behavior of new and innovative binder compositions was tested in lab tests. One possible change in mix-design is the reduction in clinker content by using a lower amount of Ordinary Portland Cement together with cementitious materials. Successful combinations were further investigated in sprayed mortar and shotcrete tests to examine the influences of the spraying process and the addition of accelerator. The results indicate how shotcrete mix-design can be improved regarding its potential for precipitations and subsequently enhanced durability of shotcrete. Y1 - 2016 SN - 978-4-9909148-0-6 SP - 221 EP - 228 PB - Technical University of Tokyo ER - TY - INPR A1 - Malz, Sebastian A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. A1 - Steffens, Oliver A1 - Kusterle, Wolfgang T1 - Determination of the Water Content within Tunnel Linings to Assess Fire Safety T2 - SSRN Electronic Journal N2 - Fires in tunnels are known to lead to explosive spalling of the tunnel linings, mainly due to rapid expansion of water as a result of vaporization in the concrete. In order to determine water content and assess fire safety within tunnel linings a novel measurement system has been developed. The development process includes the calibration of the sensor system via both direct and indirect approaches. This work compares both calibration methods and shows the differences that can occur due to measurement uncertainty. This work presents the measured water content within the Inntal tunnel, Austria as a representative tunnel from a total of four investigated tunnels. The obtained water content is compared to that found in the literature, and recommendations for practical work in terms of fire safety is given. KW - tunnel inner lining KW - water content KW - moisture sensor KW - moisture measurement KW - Fire safety KW - concrete spalling Y1 - 2023 U6 - https://doi.org/10.2139/ssrn.4390700 ER - TY - CHAP A1 - Thumann, Maria A1 - Briendl, Lukas G. A1 - Juhart, Joachim A1 - Kusterle, Wolfgang ED - Teubert, Oliver ED - Kusterle, Wolfgang ED - Greim, Markus T1 - Rheologische Untersuchungen an Frischbetonmischungen für Spritzbeton T2 - Rheologische Messungen an Baustoffen 2019 : Tagungsband zum 28. Workshop und Kolloquium, 13. und 14. März an der OTH Regensburg KW - Beton KW - Rheologie Y1 - 2019 SN - 978-3-7482-4651-0 PB - tredition CY - Hamburg ER - TY - JOUR A1 - Beimler, Josef A1 - Leißl, Caroline A1 - Ebner, Lena A1 - Elsner, Michael A1 - Mühlbauer, Gerhard A1 - Kohlert, Dieter A1 - Schubert, Martin J. W. A1 - Weiß, Andreas P. A1 - Sterner, Michael A1 - Raith, Thomas A1 - Afranseder, Martin A1 - Krapf, Tobias A1 - Mottok, Jürgen A1 - Siemers, Christian A1 - Großmann, Benjamin A1 - Höcherl, Johannes A1 - Schlegl, Thomas A1 - Schneider, Ralph A1 - Milaev, Johannes A1 - Rampelt, Christina A1 - Roduner, Christian A1 - Glowa, Christoph A1 - Bachl, Christoph A1 - Schliekmann, Claus A1 - Gnan, Alfons A1 - Grill, Martin A1 - Ruhland, Karl A1 - Piehler, Thomas A1 - Friers, Daniel A1 - Wels, Harald A1 - Pflug, Kenny A1 - Kucera, Markus A1 - Waas, Thomas A1 - Schlachetzki, Felix A1 - Boy, Sandra A1 - Pemmerl, Josef A1 - Leis, Alexander A1 - Welsch, Andreas F.X. A1 - Graf, Franz A1 - Zenger, Gerhard A1 - Volbert, Klaus A1 - Waas, Thomas A1 - Scherzinger, Stefanie A1 - Klettke, Meike A1 - Störl, Uta A1 - Heyl, C. A1 - Boldenko, A. A1 - Monkman, Gareth J. A1 - Kujat, Richard A1 - Briem, Ulrich A1 - Hierl, Stefan A1 - Talbot, Sebastian A1 - Schmailzl, Anton A1 - Ławrowski, Robert Damian A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Dams, Florian A1 - Schreiner, Rupert A1 - Valentino, Piergiorgio A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Furgiuele, Franco A1 - Gebbeken, Norbert A1 - Eisenried, Michael A1 - Jungbauer, Bastian A1 - Hutterer, Albert A1 - Bauhuber, Michael A1 - Mikrievskij, Andreas A1 - Argauer, Monika A1 - Hummel, Helmut A1 - Lechner, Alfred A1 - Liebetruth, Thomas A1 - Schumm, Michael A1 - Joseph, Saskia A1 - Reschke, Michael A1 - Soska, Alexander A1 - Schroll-Decker, Irmgard A1 - Putzer, Michael A1 - Rasmussen, John A1 - Dendorfer, Sebastian A1 - Weber, Tim A1 - Al-Munajjed, Amir Andreas A1 - Verkerke, Gijsbertus Jacob A1 - Renkawitz, Tobias A1 - Haug, Sonja A1 - Rudolph, Clarissa A1 - Zeitler, Annika A1 - Schaubeck, Simon A1 - Steffens, Oliver A1 - Rechenauer, Christian A1 - Schulz-Brize, Thekla A1 - Fleischmann, Florian A1 - Kusterle, Wolfgang A1 - Beer, Anne A1 - Wagner, Bernd A1 - Neidhart, Thomas ED - Baier, Wolfgang T1 - Forschungsbericht 2013 T3 - Forschungsberichte der OTH Regensburg - 2013 Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-7990 CY - Regensburg ER - TY - CHAP A1 - Steindl, F. A1 - Mittermayr, Florian A1 - Thumann, Maria A1 - Juhart, Joachim A1 - Galan Garcia, Isabel A1 - Baldermann, Andre A1 - Briendl, Lukas G. A1 - Sakoparnig, Marlene A1 - Röck, Rudolf A1 - Kusterle, Wolfgang T1 - Sulfate resistance of dry mix shotcretes with new binder composition T2 - ICCC 2019: 15th International Congress on the Chemistry of Cement, 16.-20.09.2019, Prague, Czech Republik N2 - Improved understanding of the mechanisms underlying deleterious chemical attacks is necessary to better predict the long-term performance and durability of shotcrete in aggressive environments. In the scope of the research project “ASSpC - Advanced and Sustainable Sprayed Concrete”, new durable and sustainable shotcretes and new test methods are developed. In order to increase shotcrete durability, the spray cement (specified in Austrian Guideline “Sprayed concrete”) used is substituted with supplementary cementitious materials (SCMs). However, in the past SCMs have seen only limited use in the application of dry-mix shotcrete. This contribution presents 6 new mix designs intended to be used for dry-mix shotcrete, each with varying amounts and types of SCMs, and compares their performance and sprayability with a commercially available spray cement. As sulfate attack is one of the major threats to shotcrete (e.g. in tunnelling), the resistance of the new mixes against sulfate attack is tested using a modified version of the Swiss sulfate test according to SIA 262/1:2013. This approach provides new insights into damaging mechanisms of dry mix shotcrete in sulfate-loaded environments Y1 - 2019 SP - 3527 EP - 3872 ER - TY - CHAP A1 - Baldermann, Andre A1 - Mittermayr, Florian A1 - Thumann, Maria A1 - Kusterle, Wolfgang T1 - Development of shotcrete with increased durability against thaumasite sulfate attack BT - Experiences from a tunnel site and laboratory tests T2 - ICCC 2019: 15th International Congress on Chemistry of Cement, 16.-20.09.2019, Prague, Czech Republik Y1 - 2019 SP - 3425 EP - 3435 ER - TY - JOUR A1 - Sakoparnig, Marlene A1 - Galan, Isabel A1 - Steindl, Florian Roman A1 - Kusterle, Wolfgang A1 - Juhart, Joachim A1 - Grengg, Cyrill A1 - Briendl, Lukas G. A1 - Saxer, Andreas A1 - Thumann, Maria A1 - Mittermayr, Florian T1 - Durability of clinker reduced shotcrete: Ca2+ leaching, sintering, carbonation and chloride penetration JF - Materials and structures N2 - The reduction of clinker use is mandatory to lower the negative environmental impact of concrete. In shotcrete mixes, similarly to the case of conventional concrete, the use of supplementary cementitious materials (SCMs) and proper mix design allow for the substitution of clinker without compromising the mechanical properties. However, the impact of the substitution on the durability of shotcrete needs to be further assessed and understood. The results from the present study, obtained from real-scale sprayed concrete applications, show a reduction of the Ca2+ leaching and sintering potential of clinker-reduced shotcrete mixes due to the presence of SCMs. This positive effect, crucial for low maintenance costs of tunnels, is mainly related to a reduced portlandite content, which on the other hand negatively affects the carbonation resistance of shotcrete. Additionally, the hydration of SCMs positively influences the chloride penetration resistance presumably due to a combination of microstructural changes and changes in the chloride binding capacity. Differences found in the pore size distribution of the various mixes have low impact on the determined durability parameters, in particular compared to the effect of inhomogeneities produced during shotcrete application. KW - Carbonate precipitation KW - Carbonation KW - Chloride penetration KW - Durability KW - Leaching KW - Shotcrete Y1 - 2021 U6 - https://doi.org/10.1617/s11527-021-01644-7 VL - 54 SP - 1 EP - 23 PB - Springer Nature ER - TY - JOUR A1 - Steindl, Florian Roman A1 - Galan, Isabel A1 - Baldermann, Andre A1 - Sakoparnig, Marlene A1 - Briendl, Lukas G. A1 - Juhart, Joachim A1 - Thumann, Maria A1 - Dietzel, Martin A1 - Röck, Rudolf A1 - Kusterle, Wolfgang A1 - Mittermayr, Florian T1 - Sulfate durability and leaching behaviour of dry- and wet-mix shotcrete mixes JF - Cement and Concrete Research N2 - Shotcrete is a material frequently used in underground constructions such as tunnels, where Ca leaching and sulfate attack are important durability issues. In this study, two test methods were employed to investigate the sulfate resistance and leaching behaviour of dry- and wet-mix shotcretes in sulfate solutions on a time-resolved basis. Tests on powdered samples showed the dissolution of AFm, portlandite and C-A-S-H, subsequently followed by the precipitation of calcite and ettringite. The extent of sulfate expansion of drill cores corresponded to the chemical response of the powder materials, particularly on the reactivity of Ca- and Al-containing hydrated cement phases. The use of high-purity metakaolin (7-10 wt%) in the shotcrete binder significantly decreased the sulfate durability, while high amounts of other SCMs such as blast-furnace slag and silica fume (> 20 wt%) had a positive effect on the durability of shotcrete. KW - ADMIXTURES KW - ALKALI-FREE KW - ATTACK KW - BLAST-FURNACE SLAG KW - concrete KW - Durability KW - Leaching KW - MECHANISM KW - METAKAOLIN KW - RESISTANCE KW - SCMs KW - Shotcrete KW - Sulfate attack KW - TEMPERATURE KW - THAUMASITE FORM Y1 - 2020 U6 - https://doi.org/10.1016/j.cemconres.2020.106180 VL - 137 IS - November SP - 1 EP - 19 PB - Elsevier ER -