@article{HaynackTimothyKraenkeletal., author = {Haynack, Alexander and Timothy, Jithender J. and Kr{\"a}nkel, Thomas and Gehlen, Christoph and Thiel, Charlotte}, title = {Analyse des Frost-Tausalz-Widerstands zementgebundener Baustoffe mittels 3D-Laserscanning}, series = {ce/papers: Proceedings in Civil Engineering}, volume = {6}, journal = {ce/papers: Proceedings in Civil Engineering}, number = {6}, publisher = {Ernst \& Sohn}, issn = {2509-7075}, doi = {10.1002/cepa.2951}, pages = {1189 -- 1196}, abstract = {Eine Herausforderung performancebasierter Pr{\"u}fverfahren zur Bewertung der Dauerhaftigkeit ist die Beschleunigung nat{\"u}rlicher Mechanismen. Dies ist notwendig, um innerhalb kurzer Zeit die Langzeit-Leistungsf{\"a}higkeit ermitteln zu k{\"o}nnen. Die Bestimmung der Frost-Tausalzbest{\"a}ndigkeit von Beton kann durch den CDF-Test erfolgen, welcher f{\"u}r Betone mit ausreichendem Frost-Tausalz-Widerstand sehr gut funktioniert. Bei Proben mit einer unzureichenden bzw. unbekannten Performance k{\"o}nnen erh{\"o}hte Randabwitterungen auftreten, welche durch das Abl{\"o}sen des seitlichen Abdichtbands entstehen. Der zunehmende Randeinfluss f{\"u}hrt so zu einer Verf{\"a}lschung der Ergebnisse und zu einer Untersch{\"a}tzung der tats{\"a}chlichen Performance des Bauteils. In diesem Beitrag werden M{\"o}rtel- und Betonprobek{\"o}rper mit unterschiedlichen Abwitterungsraten in Anlehnung an das CDF-Verfahren untersucht. Zus{\"a}tzlich wird die Oberfl{\"a}chensch{\"a}digung der Proben anhand einer neuartigen Messmethode mittels hochaufl{\"o}sendem 3D-Laserscanning ausgewertet. Die Ergebnisse zeigen, dass die Randeffekte mit der Laserscan-Methode umgangen und vergleichbare Ergebnisse zu den CDF-Untersuchungen erzielt werden k{\"o}nnen. Somit k{\"o}nnen Betone ohne Randeinfl{\"u}sse charakterisiert und eine pr{\"a}zise Prognose der Langzeitbest{\"a}ndigkeit getroffen werden.}, language = {de} } @article{GrimmThielKraenkeletal., author = {Grimm, Benedikt and Thiel, Charlotte and Kr{\"a}nkel, Thomas and Gehlen, Christoph}, title = {Einfluss der Permeation auf die Carbonatisierung von Beton}, series = {ce/papers: Proceedings in Civil Engineering}, volume = {6}, journal = {ce/papers: Proceedings in Civil Engineering}, number = {6}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {2509-7075}, doi = {10.1002/cepa.3005}, pages = {1348 -- 1357}, abstract = {Die Carbonatisierung von Beton kann einerseits zu Sch{\"a}den bei Stahlbetonbauwerken f{\"u}hren, andererseits kann der Beton so CO2 speichern und damit seinen CO2-Fußabdruck verringern. In diesem Beitrag wird dargestellt, wie eine effiziente Beschleunigung der Carbonatisierung durch Anlegen eines geringen {\"a}ußeren Drucks erreicht werden kann. Damit wird neben der Diffusion der wesentlich schneller ablaufende Transportmechanismus der Permeation ausgenutzt, der das CO2 tiefer in das Probeninnere transportiert und damit in kurzer Zeit die Bestimmung des Carbonatisierungswiderstand zementgebundener Materialien erm{\"o}glicht. Hierzu wurde eine Pr{\"u}feinrichtung entwickelt, die es erm{\"o}glicht, die CO2-Konzentration und in gewissen Grenzen auch relative Luftfeuchte sowie die Temperatur gezielt einzustellen und zu steuern, um so M{\"o}rtel- und Betonproben schnell und pr{\"a}zise zu carbonatisieren. Der Einfluss verschiedener Druckstufen und Wechselzyklen wird dargelegt und die resultierenden chemischen und physikalischen Ver{\"a}nderungen der Proben bestimmt. Als besonders effizient und gleichzeitig realit{\"a}tsnah erwies sich die konstante CO2-Beaufschlagung mit 3 Vol.-\% CO2 mit zus{\"a}tzlichem, moderatem Gasdruck. Das hier entwickelte Verfahren kann daher genutzt werden, um Betone schnell und effizient in zeitraffenden Materialtests hinsichtlich Carbonatisierungswiderstand zu charakterisieren.}, language = {en} } @inproceedings{ThielHechtlGehlenetal., author = {Thiel, Charlotte and Hechtl, C. Maximilian and Gehlen, Christoph and Kr{\"a}nkel, Thomas}, title = {Sustainability Potential of Additive Manufactured Concrete Structures - Studies on the Life Cycle Assessment and Circularity of an Extruded Exterior Wall}, series = {Fourth RILEM International Conference on Concrete and Digital Fabrication (DC 2024), Munich, Germany, September 2024}, booktitle = {Fourth RILEM International Conference on Concrete and Digital Fabrication (DC 2024), Munich, Germany, September 2024}, editor = {Lowke, Dirk and Freund, Niklas and B{\"o}hler, David and Herding, Friedrich}, publisher = {SPRINGER INTERNATIONAL PU}, isbn = {978-3-031-70030-9}, doi = {10.1007/978-3-031-70031-6_2}, pages = {13 -- 21}, abstract = {The Brundtland Report defined sustainable development as a development that meets the needs of the present without compromising the ability of future generations to meet their own needs. If this definition is applied to the construction sector, a new, circular approach to cementitious materials is required. Additive manufacturing (AM) enables to design material-efficient and monolithic structures that meet physical and chemical requirements of building standards while allowing reuse or high-quality recycling of concrete. Here, the environmental impact as well as the circularity potential of an additively manufactured exterior wall, produced by 3D concrete extrusion, are determined. To classify the results, the additively manufactured exterior wall is compared with a conventional concrete construction. Finally, various options for optimizing the printed wall are considered and evaluated. Additive manufacturing enabled significant material savings compared to conventional construction. The environmental impacts strongly depend on the used concrete composition. For example, greenhouse gas emissions could be reduced by 20\% when changing the type of lightweight aggregate. The additively manufactured exterior wall exhibited advantages in terms of circularity. Through further development and research, additive manufacturing of concrete can promote a paradigm shift towards sustainable practices.}, language = {en} } @inproceedings{ThumannBriendlJuhartetal., author = {Thumann, Maria and Briendl, Lukas G. and Juhart, Joachim and Kusterle, Wolfgang}, title = {Rheologische Untersuchungen an Frischbetonmischungen f{\"u}r Spritzbeton}, series = {Rheologische Messungen an Baustoffen 2019 : Tagungsband zum 28. Workshop und Kolloquium, 13. und 14. M{\"a}rz an der OTH Regensburg}, booktitle = {Rheologische Messungen an Baustoffen 2019 : Tagungsband zum 28. Workshop und Kolloquium, 13. und 14. M{\"a}rz an der OTH Regensburg}, editor = {Teubert, Oliver and Kusterle, Wolfgang and Greim, Markus}, publisher = {tredition}, address = {Hamburg}, isbn = {978-3-7482-4651-0}, pages = {95 ff.}, language = {de} } @inproceedings{SteindlMittermayrThumannetal., author = {Steindl, F. and Mittermayr, Florian and Thumann, Maria and Juhart, Joachim and Galan Garcia, Isabel and Baldermann, Andre and Briendl, Lukas G. and Sakoparnig, Marlene and R{\"o}ck, Rudolf and Kusterle, Wolfgang}, title = {Sulfate resistance of dry mix shotcretes with new binder composition}, series = {ICCC 2019: 15th International Congress on the Chemistry of Cement, 16.-20.09.2019, Prague, Czech Republik}, booktitle = {ICCC 2019: 15th International Congress on the Chemistry of Cement, 16.-20.09.2019, Prague, Czech Republik}, pages = {3527 -- 3872}, abstract = {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}, language = {en} } @inproceedings{BaldermannMittermayrThumannetal., author = {Baldermann, Andre and Mittermayr, Florian and Thumann, Maria and Kusterle, Wolfgang}, title = {Development of shotcrete with increased durability against thaumasite sulfate attack}, series = {ICCC 2019: 15th International Congress on Chemistry of Cement, 16.-20.09.2019, Prague, Czech Republik}, booktitle = {ICCC 2019: 15th International Congress on Chemistry of Cement, 16.-20.09.2019, Prague, Czech Republik}, pages = {3425 -- 3435}, language = {en} } @article{VonGreveDierfeldLothenbachVollprachtetal., author = {Von Greve-Dierfeld, Stefanie and Lothenbach, Barbara and Vollpracht, Anya and Wu, Bei and Huet, Bruno and Andrade, Carmen and Medina, C{\´e}sar and Thiel, Charlotte and Gruyaert, Elke and Vanoutrive, Hanne and Del Sa{\´e}z Bosque, Isabel F. and Ignjatovic, Ivan and Elsen, Jan and Provis, John L. and Scrivener, Karen and Thienel, Karl-Christian and Sideris, Kosmas and Zajac, Maciej and Alderete, Natalia and Cizer, {\"O}zlem and Van den Heede, Philip and Hooton, Robert Douglas and Kamali-Bernard, Siham and Bernal, Susan A. and Zhao, Zengfeng and Shi, Zhenguo and De Belie, Nele}, title = {Understanding the carbonation of concrete with supplementary cementitious materials}, series = {Materials and Structures}, volume = {53}, journal = {Materials and Structures}, publisher = {Springer Nature}, doi = {10.1617/s11527-020-01558-w}, pages = {1 -- 34}, abstract = {Blended cements, where Portland cement clinker is partially replaced by supplementary cementitious materials (SCMs), provide the most feasible route for reducing carbon dioxide emissions associated with concrete production. However, lowering the clinker content can lead to an increasing risk of neutralisation of the concrete pore solution and potential reinforcement corrosion due to carbonation. carbonation of concrete with SCMs differs from carbonation of concrete solely based on Portland cement (PC). This is a consequence of the differences in the hydrate phase assemblage and pore solution chemistry, as well as the pore structure and transport properties, when varying the binder composition, age and curing conditions of the concretes. The carbonation mechanism and kinetics also depend on the saturation degree of the concrete and CO2 partial pressure which in turn depends on exposure conditions (e.g. relative humidity, volume, and duration of water in contact with the concrete surface and temperature conditions). This in turn influence the microstructural changes identified upon carbonation. This literature review, prepared by members of RILEM technical committee 281-CCC carbonation of concrete with supplementary cementitious materials, working groups 1 and 2, elucidates the effect of numerous SCM characteristics, exposure environments and curing conditions on the carbonation mechanism, kinetics and structural alterations in cementitious systems containing SCMs.}, language = {en} } @article{SakoparnigGalanSteindletal., author = {Sakoparnig, Marlene and Galan, Isabel and Steindl, Florian Roman and Kusterle, Wolfgang and Juhart, Joachim and Grengg, Cyrill and Briendl, Lukas G. and Saxer, Andreas and Thumann, Maria and Mittermayr, Florian}, title = {Durability of clinker reduced shotcrete: Ca2+ leaching, sintering, carbonation and chloride penetration}, series = {Materials and structures}, volume = {54}, journal = {Materials and structures}, publisher = {Springer Nature}, doi = {10.1617/s11527-021-01644-7}, pages = {1 -- 23}, abstract = {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.}, language = {en} } @article{SteindlGalanBaldermannetal., author = {Steindl, Florian Roman and Galan, Isabel and Baldermann, Andre and Sakoparnig, Marlene and Briendl, Lukas G. and Juhart, Joachim and Thumann, Maria and Dietzel, Martin and R{\"o}ck, Rudolf and Kusterle, Wolfgang and Mittermayr, Florian}, title = {Sulfate durability and leaching behaviour of dry- and wet-mix shotcrete mixes}, series = {Cement and Concrete Research}, volume = {137}, journal = {Cement and Concrete Research}, number = {November}, publisher = {Elsevier}, doi = {10.1016/j.cemconres.2020.106180}, pages = {1 -- 19}, abstract = {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.}, language = {en} } @article{GalanBriendlThumannetal., author = {Galan, Isabel and Briendl, Lukas G. and Thumann, Maria and Steindl, Florian and Roeck, Rudolf and Kusterle, Wolfgang and Mittermayr, Florian}, title = {Filler Effect in Shotcrete}, series = {Materials}, volume = {12}, journal = {Materials}, number = {19}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/ma12193221}, pages = {1 -- 24}, abstract = {The effects of fine limestone powder on the early hydration of cementitious systems accelerated by means of alkali-free aluminum sulfate based products, commonly used for shotcrete applications, were investigated in the course of laboratory and real scale tests. In binary (CEM I + limestone) and ternary (CEM I + limestone + slag) systems the addition of fine limestone led to an enhancement of the hydration degree and strength development at early times (<24 h). The formation of ettringite, aluminate hydrates, and C-S-H is affected by the joint action of the setting accelerator and the fine limestone. Accelerator and limestone, in combination with the cement, can be optimized to enhance ettringite and silicate reaction, in some cases coupled with aluminate reaction inhibition, to produce mixes suitable for sprayed concrete applications. Such optimization can help to reduce the cement content in the mixes without compromising the early strength development of the shotcrete.}, language = {en} } @inproceedings{MittermayrGalanSaadeetal.2019, author = {Mittermayr, Florian and Galan, Isabel and Saade, Marcella Ruschi Mendes and Saxer, Andreas and Kusterle, Wolfgang}, title = {"ASSpC" Shotcrete research for the needs of tomorrow}, series = {ICCC 2019: 15th International Congress on the Chemistry of Cement, ICCC 2019, 16.-20.09.2019, Prague, Czech Republik}, booktitle = {ICCC 2019: 15th International Congress on the Chemistry of Cement, ICCC 2019, 16.-20.09.2019, Prague, Czech Republik}, pages = {3518 -- 3872}, year = {2019}, abstract = {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.}, language = {en} } @inproceedings{SakoparnigGalanBaldermanetal., author = {Sakoparnig, Marlene and Galan, Isabel and Balderman, Andre and Steindl, Florian and Dietzel, Martin and Thumann, Maria and Saxer, Andreas and Kusterle, Wolfgang and Mittermayr, Florian}, title = {Experimental Ca leaching of shotcrete \& secondary precipitation}, series = {ICCC 2019: 15th International Congress on the Chemistry of Cement, ICCC 2019, 16.-20.09.2019, Prague, Czech Republik}, booktitle = {ICCC 2019: 15th International Congress on the Chemistry of Cement, ICCC 2019, 16.-20.09.2019, Prague, Czech Republik}, pages = {3488 -- 3495}, language = {en} } @inproceedings{BriendlGalanSteindletal., author = {Briendl, Lukas G. and Galan, Isabel and Steindl, Florian and R{\"o}ck, Rudolf and Thumann, Maria and Juhart, Joachim and Baldermann, Andre and Mittermayr, Florian and Kusterle, Wolfgang}, title = {Hydration processes of accelerated cementitious systems governing early strength development}, series = {ICCC 2019: 15th International Congress on Chemistry of Cement, 16.-20.09.2019, Prague, Czech Republik}, booktitle = {ICCC 2019: 15th International Congress on Chemistry of Cement, 16.-20.09.2019, Prague, Czech Republik}, pages = {714 -- 724}, language = {en} } @inproceedings{JuhartBriendlRoecketal., author = {Juhart, Joachim and Briendl, Lukas G. and R{\"o}ck, Rudolf and Galan, Isabel and Thumann, Maria and Mittermayr, Florian and Kusterle, Wolfgang}, title = {Performance optimization of shotcrete by combined fillers}, series = {ICCC 2019: 15th International Congress on the Chemistry of Cement, ICCC 2019, 16.-20.09.2019, Prague, Czech Republik}, booktitle = {ICCC 2019: 15th International Congress on the Chemistry of Cement, ICCC 2019, 16.-20.09.2019, Prague, Czech Republik}, pages = {1387 -- 3872}, language = {en} } @article{SakoparnigGalanKusterleetal., author = {Sakoparnig, Marlene and Galan, Isabel and Kusterle, Wolfgang and Lindlar, Benedikt and Koraimann, G{\"u}nther and Angerer, Thomas and Steindl, Florian Roman and Briendl, Lukas G. and Jehle, Sebastian and Flotzinger, Johannes and Juhart, Joachim and Mittermayr, Florian}, title = {On the significance of accelerator enriched layers in wet-mix shotcrete}, series = {Tunnelling and Underground Space Technology}, volume = {131}, journal = {Tunnelling and Underground Space Technology}, publisher = {Elsevier}, doi = {10.1016/j.tust.2022.104764}, pages = {1 -- 10}, abstract = {The application process, which gives shotcrete its name is a robust and established method, dating back to the beginning of the 20th century. Since then, the spraying process has been significantly enhanced. However, during the last decades no major technical changes have been made. In this study the wet - mix shotcrete process including the dosing of accelerator was investigated. For this, we monitored the concrete and accelerator pressure with 5 sensors in the pumps and pipes, and analysed the accelerator distribution in the hardened shotcrete matrix. The recorded pressure fluctuations clearly indicated that the pumping of the concrete with a double-piston pump led to flow pulsations. The pressure along the accelerator pipes, controlled by a peristaltic pump, was not steady either. However, the accelerator flow pulsation had a higher frequency than that of the concrete flow. This misalignment led to changes in the accelerator to concrete ratio during the spraying process. The impact of these incongruent concrete and accelerator flows on the resulting hardened shotcrete was visually analysed with the use of 0.02 \% uranin as fluorescent tracer added to the accelerator. The tracer distribution showed that changes in the accelerator/concrete ratio led to the formation of 'accelerator layers', layers with higher accelerator concentrations in the hardened shotcrete. These layers show differences in chemistry, mineralogy and open porosity compared to the rest of the shotcrete matrix. The presence of accelerator enriched layers can have detrimental effects on the shotcrete properties, especially affecting the durability and mechanical performance. In consequence, we recommend a revision of the shotcrete process to eliminate these inhomogeneities.}, language = {en} } @inproceedings{SakoparnigBaldermannThumannetal., author = {Sakoparnig, Marlene and Baldermann, Andre and Thumann, Maria and Mittermayr, Florian and Kusterle, Wolfgang}, title = {Bestimmung der experimentellen Calcium-Auslaugung an Spritzbetonbohrkernen: Methodenvergleich und Update}, series = {Spritzbeton-Tagung 2018, Alpbach, {\"O}sterreich 11.-12.01.2018}, booktitle = {Spritzbeton-Tagung 2018, Alpbach, {\"O}sterreich 11.-12.01.2018}, abstract = {Im Rahmen des FFG-Forschungsprojektes „Entwicklung neuer dauerhafter und nachhaltiger Spritzbetone (Advanced and sustainable sprayed concrete; ASSpC)" werden Methoden zur Pr{\"u}fung der Calcium-Auslaugung von Spritzbeton eingesetzt bzw. weiterentwickelt. Bestimmt wurde daf{\"u}r das Reduzierte Versinterungspotential nach Regelwerken der {\"O}sterreichischen Bautechnik Vereinigung und das Auslaugverhalten von Spritzbeton bei leichtem S{\"a}ureangriff (Salpeters{\"a}ure und Kohlens{\"a}ure), um dauerhaftigkeitsrelevante Parameter im Bereich der Wechselwirkungen von Spritzbeton mit leicht sauren (Kohlens{\"a}ure- und Nitrathaltigen) Oberfl{\"a}chen-, Grund- und Sickerw{\"a}ssern zu untersuchen und potentielle Sch{\"a}digungsmechanismen zu identifizieren und zu quantifizieren. Die Vor- und Nachteile der verwendeten Pr{\"u}fmethoden zum l{\"o}senden Angriff werden in Bezug auf die Dauerhaftigkeit von Spritzbeton diskutiert.}, language = {de} } @misc{PfahlerNeidhartHuettneretal., author = {Pfahler, Katharina and Neidhart, Thomas and H{\"u}ttner, Susanne and Thiel, Charlotte}, title = {Vom Boden zur Wand - Stand der Technik und zuk{\"u}nftige Entwicklungen}, series = {LEHM 2024, 9. Internationale Fachtagung f{\"u}r Lehmbau, 27.-29.9.2024, Weimar}, journal = {LEHM 2024, 9. Internationale Fachtagung f{\"u}r Lehmbau, 27.-29.9.2024, Weimar}, publisher = {Eigenverlag Dachverband Lehm e.V.}, address = {Weimar}, isbn = {978-3-00-079502-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-78400}, pages = {8}, abstract = {Lehm selbst ist ein Baustoff mit zahlreichen Vorteilen (diffusionsoffen, wiederverwendbar, hohe Verf{\"u}gbarkeit, geringe graue Emissionen, guter Schallschutz und hohe Dauerhaftigkeit bei fachgerechtem Einsatz), aber auch Grenzen in der Anwendbarkeit, die sich aus Schwund, begrenzter Lastaufnahme und hoher W{\"a}rmeleitf{\"a}higkeit (und damit geringer W{\"a}rmed{\"a}mmwirkung) ergeben. Aus Lehm und damit aus Boden Wandbaustoff zu fertigen, funktioniert sowohl im Bereich des Trockenausbaus (Lehmbauplatten, Lehmputz) als auch des tragendes Mauerwerks sehr gut und gewinnt durch die k{\"u}rzlich eingef{\"u}hrten Normen an neuem Aufschwung. Die tragende Stampflehmbauweise mit lokal ausgehobenem Material ist bedingt durch den hohen handwerklichen Aufwand bei gleichzeitigem Fachkr{\"a}ftemangel und erforderlichen Zustimmung im Einzelfall oder vorhabensbezogener Bauartgenehmigung kosten- und zeitintensiv. Dabei bringt sie bauphysikalisch und {\"o}kologisch h{\"a}ufig signifikante Vorteile im Vergleich zu konventionellen Bauweisen mit sich. Dieser Beitrag stellt daher anhand einer ausf{\"u}hrlichen Literaturrecherche und eigenen Versuchen den Stand der Technik industrieller Lehmbaustoffe dar. Fokus des Beitrags liegt auf M{\"o}glichkeiten, die Stampflehmbauweise zu neuer und wirtschaftlicher Leistungsf{\"a}higkeit zu bringen.}, subject = {Lehmbau}, language = {de} } @inproceedings{KusterleThumannMittermayr, author = {Kusterle, Wolfgang and Thumann, Maria and Mittermayr, Florian}, title = {ASSpC - Ein Forschungsprogramm f{\"u}r den Spritzbeton von morgen}, series = {Tagungs-CD der Spritzbeton-Tagung 2018, 11.-12. Januar 2018, Alpbach, Tirol, CD-ROM}, booktitle = {Tagungs-CD der Spritzbeton-Tagung 2018, 11.-12. Januar 2018, Alpbach, Tirol, CD-ROM}, abstract = {Spritzbeton wird im Tunnelbau als tempor{\"a}re und permanente St{\"u}tz- und Ausbaumaßnahme eingesetzt. Mit der Einf{\"u}hrung der alkalifreien Spritzbeton-Technologie wurde um 2004 ein großer Qualit{\"a}tssprung erzielt. Trotzdem besteht noch Optimierungsbedarf. Alle Bauwerke sollten heute nachhaltig und dauerhaft erstellt werden. Spritzbeton sollte daher aus m{\"o}glichst umweltneutralen Stoffen hergestellt werden und auch in aggressiver Umgebung dauerhaft, ohne ung{\"u}nstige Auswirkungen auf das Gesamtbauwerk, seine Aufgaben erf{\"u}llen. Das kann nur mit optimierten Rezepturen unter Einsatz ausgew{\"a}hlter Ausgangsstoffe realisiert werden. Das von der FFG in {\"O}sterreich gef{\"o}rderte Forschungsprogramm „Entwicklung neuer dauerhafter und nachhaltiger Spritzbetone" (Advanced and Sustainable Sprayed Concrete) setzt genau hier an.}, language = {de} } @article{VanoutriveVandenHeedeAldereteetal., author = {Vanoutrive, Hanne and Van den Heede, Philip and Alderete, Natalia and Andrade, Carmen and Bansal, Tushar and Cam{\~o}es, Aires and Cizer, {\"O}zlem and De Belie, Nele and Ducman, Vilma and Etxeberria, Miren and Frederickx, Lander and Grengg, Cyrill and Ignjatović, Ivan and Ling, Tung-Chai and Liu, Zhiyuan and Garcia-Lodeiro, In{\´e}s and Lothenbach, Barbara and Medina Martinez, C{\´e}sar and Sanchez-Montero, Javier and Olonade, Kolawole Adisa and Palomo, Angel and Phung, Quoc Tri and Rebolledo, Nuria and Sakoparnig, Marlene and Sideris, Kosmas and Thiel, Charlotte and Visalakshi, Talakokula and Vollpracht, Anya and Von Greve-Dierfeld, Stefanie and Wei, Jinxin and Wu, Bei and Zając, Maciej and Zhao, Zengfeng and Gruyaert, Elke}, title = {Report of RILEM TC 281-CCC: outcomes of a round robin on the resistance to accelerated carbonation of Portland, Portland-fly ash and blast-furnace blended cements}, series = {Materials and Structures}, volume = {55}, journal = {Materials and Structures}, number = {3}, publisher = {Springer}, doi = {10.1617/s11527-022-01927-7}, pages = {1 -- 29}, abstract = {Many (inter)national standards exist to evaluate the resistance of mortar and concrete to carbonation. When a carbonation coefficient is used for performance comparison of mixtures or service life prediction, the applied boundary conditions during curing, preconditioning and carbonation play a crucial role, specifically when using latent hydraulic or pozzolanic supplementary cementitious materials (SCMs). An extensive interlaboratory test (ILT) with twenty two participating laboratories was set up in the framework of RILEM TC 281-CCC 'Carbonation of Concrete with SCMs'. The carbonation depths and coefficients determined by following several (inter)national standards for three cement types (CEM I, CEM II/B-V, CEM III/B) both on mortar and concrete scale were statistically compared. The outcomes of this study showed that the carbonation rate based on the carbonation depths after 91 days exposure, compared to 56 days or less exposure duration, best approximates the slope of the linear regression and those 91 days carbonation depths can therefore be considered as a good estimate of the potential resistance to carbonation. All standards evaluated in this study ranked the three cement types in the same order of carbonation resistance. Unfortunately, large variations within and between laboratories complicate to draw clear conclusions regarding the effect of sample pre-conditioning and carbonation exposure conditions on the carbonation performance of the specimens tested. Nevertheless, it was identified that fresh and hardened state properties alone cannot be used to infer carbonation resistance of the mortars or concretes tested. It was also found that sealed curing results in larger carbonation depths compared to water curing. However, when water curing was reduced from 28 to 3 or 7 days, higher carbonation depths compared to sealed curing were observed. This increase is more pronounced for CEM I compared to CEM III mixes. The variation between laboratories is larger than the potential effect of raising the CO2 concentration from 1 to 4\%. Finally, concrete, for which the aggregate-to-cement factor was increased by 1.79 in comparison with mortar, had a carbonation coefficient 1.18 times the one of mortar. Supplementary Information The online version contains supplementary material available at 10.1617/s11527-022-01927-7.}, language = {en} } @inproceedings{MittermayrThumannBaldermannetal., author = {Mittermayr, Florian and Thumann, Maria and Baldermann, Andre and Lindlar, Benedikt and Stenger, Christian and Huber, Helmut and Bauer, Eric and Scheutz, Rudolf and Kusterle, Wolfgang}, title = {Instandsetzung Bosruck-Eisenbahntunnel:Entwicklung von Spritzbeton mit erh{\"o}htem Widerstand gegen Thaumasit-Sulfatangriff}, series = {Spritzbeton-Tagung 2018. Alpbach, Tirol, 11. und 12. Januar 2018. Tagungsbeitr{\"a}ge. CD-ROM}, booktitle = {Spritzbeton-Tagung 2018. Alpbach, Tirol, 11. und 12. Januar 2018. Tagungsbeitr{\"a}ge. CD-ROM}, address = {Oberperfuss}, abstract = {Im Bosruck-Eisenbahntunnel kam es in Folge v on intensivem Sulfatangriff durch Thaumasitbildungen zu erheblichen Betonsch{\"a}den. Bisher sieht das Regelwerk ({\"O}NORM B 4710-1 und {\"O}VBB-RL Spritzbeton) bei Sulfatangriff den Einsatz von C 3A-freien Bindemitteln vor - dies gilt auch f{\"u}r 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 erh{\"o}htem Widerstand gegen Thaumasit-Sulfatangriff und ausreichender Fr{\"u}hfestigkeit zu entwickeln. In diesem Beitrag werden neu entwickelte Mischungsans{\"a}tze und deren Umsetzung im Labormaßstab vorgestellt. Die mechanischen Kennwerte dieser Rezeptur (z.B. Fr{\"u}hfestigkeitsentwicklung) sowie die Ergebnisse der Dauerhaftigkeitsuntersuchungen zeigen, dass eine Rezeptur mit optimiertem Bindemittelgehalt die hohen Anforderungen im Tunnel erf{\"u}llen kann. Die Erfahrungen aus der praktischen Umsetzung im Zuge der Instandsetzungsarbeiten des Bosruck-Eisenbahntunnels im Jahre 2016 waren positiv.}, language = {de} }