TY - JOUR A1 - Scharfenberg, Georg A1 - Mottok, Jürgen A1 - Artmann, Christina A1 - Hobelsberger, Martin A1 - Paric, Ivan A1 - Großmann, Benjamin A1 - Pohlt, Clemens A1 - Wackerbarth, Alena A1 - Pausch, Uli A1 - Heidrich, Christiane A1 - Fadanelli, Martin A1 - Elsner, Michael A1 - Pöcher, Daniel A1 - Pittroff, Lenz A1 - Beer, Stefan A1 - Brückl, Oliver A1 - Haslbeck, Matthias A1 - Sterner, Michael A1 - Thema, Martin A1 - Muggenthaler, Nicole A1 - Lenck, Thorsten A1 - Götz, Philipp A1 - Eckert, Fabian A1 - Deubzer, Michael A1 - Stingl, Armin A1 - Simsek, Erol A1 - Krämer, Stefan A1 - Großmann, Benjamin A1 - Schlegl, Thomas A1 - Niedersteiner, Sascha A1 - Berlehner, Thomas A1 - Joblin, Mitchell A1 - Mauerer, Wolfgang A1 - Apel, Sven A1 - Siegmund, Janet A1 - Riehle, Dirk A1 - Weber, Joachim A1 - Palm, Christoph A1 - Zobel, Martin A1 - Al-Falouji, Ghassan A1 - Prestel, Dietmar A1 - Scharfenberg, Georg A1 - Mandl, Roland A1 - Deinzer, Arnulf A1 - Halang, W. A1 - Margraf-Stiksrud, Jutta A1 - Sick, Bernhard A1 - Deinzer, Renate A1 - Scherzinger, Stefanie A1 - Klettke, Meike A1 - Störl, Uta A1 - Wiech, Katharina A1 - Kubata, Christoph A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. A1 - Dollinger, Markus A1 - Dembianny, Sven A1 - Kölbl, Andreas A1 - Welker, Franz A1 - Meier, Matthias A1 - Thumann, Philipp A1 - Swidergal, Krzysztof A1 - Wagner, Marcus A1 - Haug, Sonja A1 - Vernim, Matthias A1 - Seidenstücker, Barbara A1 - Weber, Karsten A1 - Arsan, Christian A1 - Schone, Reinhold A1 - Münder, Johannes A1 - Schroll-Decker, Irmgard A1 - Dillinger, Andrea Elisabeth A1 - Fuchshofer, Rudolf A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail A1 - Geith, Markus A. A1 - Koch, Fabian A1 - Ühlin, Christian A1 - Schratzenstaller, Thomas A1 - Saßmannshausen, Sean Patrick A1 - Auchter, Eberhard A1 - Kriz, Willy A1 - Springer, Othmar A1 - Thumann, Maria A1 - Kusterle, Wolfgang A1 - Obermeier, Andreas A1 - Udalzow, Anton A1 - Schmailzl, Anton A1 - Hierl, Stefan A1 - Langer, Christoph A1 - Schreiner, Rupert ED - Baier, Wolfgang T1 - Forschungsbericht 2015 T3 - Forschungsberichte der OTH Regensburg - 2015 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-13867 SN - 978-3-00-048589-3 CY - Regensburg ER - TY - JOUR A1 - Steindl, Florian Roman A1 - Sakoparnig, Marlene A1 - Briendl, Lukas G. A1 - Thumann, Maria A1 - Galan, Isabel A1 - Juhart, Joachim A1 - Röck, Rudolf A1 - Saxer, Andreas A1 - Mittermayr, Florian A1 - Kusterle, Wolfgang T1 - ASSpC – Vier Jahre Forschung für dauerhaften Spritzbeton JF - Bautechnik Y1 - 2020 PB - Wilhelm Ernst & Sohn CY - Berlin ER - TY - JOUR A1 - Thumann, Maria A1 - Christlmeier, Peter A1 - Hartmeier, Michael A1 - Kusterle, Wolfgang T1 - Reduzierung von versinterungsbedingten Reinigungsarbeiten in Tunneldränagen durch Optimierung der Spritzbetonrezeptur JF - Beton N2 - Die Drainageleitungen in nicht druckwasserhaltenden Tunnelbauwerken haben die Aufgabe, anfallendes Bergwasser zu sammeln und aus dem Bauwerk zu führen. In den Leitungen treten häufig Kalkablagerungen, so genannte Versinterungen auf, die zu einem Teil- oder Vollverschluss der Rohre führen können und die Ableitung des Bergwassers be- bzw. verhindern. Zur Vermeidung von Schäden am Tunnelbauwerk sind regelmäßige und aufwendige Unterhaltsarbeiten notwendig. Ein wichtiger Einflussfaktor bei der Entstehung von Versinterungen ist der Kontakt des Bergwassers mit zementgebundenen Baustoffen, wie z. B. mit Spritzbeton. Aus dem Spritzbeton kann Calciumhydroxid ausgelaugt werden, das für den Korrosionsschutz der Bewehrung erforderlich ist, aber die Entstehung von Versinterungen begünstigen kann. Im Rahmen eines Forschungsprojekts wurden zahlreiche Mischungszusammensetzungen auf ihr Auslaugverhalten untersucht und Spritzbetonzusammensetzungen mit einem möglichst geringen Versinterungspotenzial entwickelt. KW - Auslaugung KW - Spritzbeton KW - Tunnelbau Y1 - 2019 VL - 68 IS - 11 SP - 416 EP - 421 PB - VERLAG BAU + TECHNIK ER - TY - CHAP A1 - Kusterle, Wolfgang A1 - Thumann, Maria ED - Beck, Thomas ED - Myren, Synnøve A. ED - Engen, Siri T1 - Pumpability of wet mixsprayed concrete with reduced clinker content T2 - 8th International Symposium on Sprayed Concrete : Modern Use of Wet Mix Sprayed Concrete for Underground Support, 11.- 14.06.2018, Trondheim, Norwegen N2 - The research project „Advanced and Sustainable Shotcrete - ASSpC“ aims at the improvement of sprayed concrete mix design regarding durability and sustainability. One possible improvement is to replace part of the clinker content in the binder with different supplementary cementitious materials. It is crucial that new mix designs fulfil the basic technical requirements on site concerning workability and early age development, too. One central issue of the project is to investigate which parameters influence the pumpability of sprayed concrete. Several test methods are used to determine the stability, tendency to segregation, bleeding and of course the consistency of concrete. An essential test method is a concrete sliding pipe rheometer (Sliper). This rheometer determines the pumping characteristics of concrete in the laboratory and on construction site. In comparison to other rheometers, the Sliper evaluates the rheological characteristics of the thin layer of paste which is lubricating the wall of the convey ing pipe. The paper presents the tests procedures in detail as well as first results from lab-tests and from site-tests with different advanced shotcrete mix-designs . Y1 - 2018 UR - https://betong.net/wp-content/uploads/8th-Sprayed-Concrete_Web-Proceedings.pdf SN - 978-82-8208-060-6 ER - TY - CHAP A1 - Thumann, Maria A1 - Kusterle, Wolfgang ED - Mähner, Dietmar ED - Beisler, Matthias ED - Heimbecher, Frank T1 - Durable and Sustainable Shotcrete – Requirements Concerning Workability and Early Strength Development T2 - Shotcrete for Underground Support XIII : New Developments in Rock Engineering, Tunneling, Underground Space and Deep Excavation [Conference Sept. 3-6, 2017] N2 - Nowadays there is a special need to develop “new” construction materials to reduce the environmental footprint of structures. Investigations focus on durability of constructions and the use of sustainable materials and the reduction of CO2 emission (especially of the binder). Constructions have to be sustainable and durable. This will lead to low maintenance work and costs as well as a good life cycle performance. The aim of the Austrian research project „Advanced and Sustainable Shotcrete - ASSpC“ is to improve shotcrete mix design regarding durability and sustainability. There are different ways which may lead to success, one possibility is to replace part of the clinker content in the binder with supplementary cementitious materials. But it is crucial that new mix designs fulfil the technical requirements on site concerning workability and early age strength development, too. One central issue of the research project is to investigate how the pumpability of shotcrete can be determined in lab. At the moment there is no proven method available to measure the pumpability of shotcrete. Several test methods are used to determine the stability, tendency to segregation, bleeding and of course the consistency of concrete. Common test methods like the spread flow table and V-funnel flow time are used as well as two point test methods like the concrete rheometer eBT2 and Sliper. The segregation tendency is evaluated by the filter pressing test and the bucket setting test. Results from lab will be compared to results from site to define threshold values and parameters which describe the pumping characteristics of shotcrete base mix. In addition to that the early age strength development of the shotcrete mix design is investigated with the Minishot System designed by Sika. The shotcrete system is downscaled to a mini spray unit. In opposite to common test methods it is not necessary to mix the accelerator into the cement paste or mortar, but it will be added at the nozzle. The paste is sprayed by a downscaled nozzle and thus a realistic shear stress can be achieved. The paste is applied to a pulsment ultrasound spectrometer and the shear modulus development is measured continuously over time. The results can be linked to the strength development of shotcrete. The paper presents the tests procedures mentioned above in detail as well as first results with different shotcrete mix-designs. Y1 - 2017 UR - https://dc.engconfintl.org/shotcrete_xiii/7/ 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 - 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 - 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 -