@article{HarirchianJadhavMohammadetal., author = {Harirchian, Ehsan and Jadhav, Kirti and Mohammad, Kifaytullah and Aghakouchaki Hosseini, Seyed Ehsan and Lahmer, Tom}, title = {A Comparative Study of MCDM Methods Integrated with Rapid Visual Seismic Vulnerability Assessment of Existing RC Structures}, series = {Applied Sciences}, volume = {2020}, journal = {Applied Sciences}, number = {Volume 10, issue 18, article 6411}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app10186411}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200918-42360}, pages = {24}, abstract = {Recently, the demand for residence and usage of urban infrastructure has been increased, thereby resulting in the elevation of risk levels of human lives over natural calamities. The occupancy demand has rapidly increased the construction rate, whereas the inadequate design of structures prone to more vulnerability. Buildings constructed before the development of seismic codes have an additional susceptibility to earthquake vibrations. The structural collapse causes an economic loss as well as setbacks for human lives. An application of different theoretical methods to analyze the structural behavior is expensive and time-consuming. Therefore, introducing a rapid vulnerability assessment method to check structural performances is necessary for future developments. The process, as mentioned earlier, is known as Rapid Visual Screening (RVS). This technique has been generated to identify, inventory, and screen structures that are potentially hazardous. Sometimes, poor construction quality does not provide some of the required parameters; in this case, the RVS process turns into a tedious scenario. Hence, to tackle such a situation, multiple-criteria decision-making (MCDM) methods for the seismic vulnerability assessment opens a new gateway. The different parameters required by RVS can be taken in MCDM. MCDM evaluates multiple conflicting criteria in decision making in several fields. This paper has aimed to bridge the gap between RVS and MCDM. Furthermore, to define the correlation between these techniques, implementation of the methodologies from Indian, Turkish, and Federal Emergency Management Agency (FEMA) codes has been done. The effects of seismic vulnerability of structures have been observed and compared.}, subject = {Erdbebensicherheit}, language = {en} } @unpublished{KhosraviSheikhKhozaniMao, author = {Khosravi, Khabat and Sheikh Khozani, Zohreh and Mao, Luka}, title = {A comparison between advanced hybrid machine learning algorithms and empirical equations applied to abutment scour depth prediction}, doi = {10.25643/bauhaus-universitaet.4388}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210311-43889}, pages = {43}, abstract = {Complex vortex flow patterns around bridge piers, especially during floods, cause scour process that can result in the failure of foundations. Abutment scour is a complex three-dimensional phenomenon that is difficult to predict especially with traditional formulas obtained using empirical approaches such as regressions. This paper presents a test of a standalone Kstar model with five novel hybrid algorithm of bagging (BA-Kstar), dagging (DA-Kstar), random committee (RC-Kstar), random subspace (RS-Kstar), and weighted instance handler wrapper (WIHWKstar) to predict scour depth (ds) for clear water condition. The dataset consists of 99 scour depth data from flume experiments (Dey and Barbhuiya, 2005) using abutment shapes such as vertical, semicircular and 45◦ wing. Four dimensionless parameter of relative flow depth (h/l), excess abutment Froude number (Fe), relative sediment size (d50/l) and relative submergence (d50/h) were considered for the prediction of relative scour depth (ds/l). A portion of the dataset was used for the calibration (70\%), and the remaining used for model validation. Pearson correlation coefficients helped deciding relevance of the input parameters combination and finally four different combinations of input parameters were used. The performance of the models was assessed visually and with quantitative metrics. Overall, the best input combination for vertical abutment shape is the combination of Fe, d50/l and h/l, while for semicircular and 45◦ wing the combination of the Fe and d50/l is the most effective input parameter combination. Our results show that incorporating Fe, d50/l and h/l lead to higher performance while involving d50/h reduced the models prediction power for vertical abutment shape and for semicircular and 45◦ wing involving h/l and d50/h lead to more error. The WIHW-Kstar provided the highest performance in scour depth prediction around vertical abutment shape while RC-Kstar model outperform of other models for scour depth prediction around semicircular and 45◦ wing.}, subject = {maschinelles Lernen}, language = {en} } @article{AlaladeReichertKoehnetal., author = {Alalade, Muyiwa and Reichert, Ina and K{\"o}hn, Daniel and Wuttke, Frank and Lahmer, Tom}, title = {A Cyclic Multi-Stage Implementation of the Full-Waveform Inversion for the Identification of Anomalies in Dams}, series = {Infrastructures}, volume = {2022}, journal = {Infrastructures}, number = {Volume 7, issue 12, article 161}, editor = {Qu, Chunxu and Gao, Chunxu and Zhang, Rui and Jia, Ziguang and Li, Jiaxiang}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/infrastructures7120161}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20221201-48396}, pages = {19}, abstract = {For the safe and efficient operation of dams, frequent monitoring and maintenance are required. These are usually expensive, time consuming, and cumbersome. To alleviate these issues, we propose applying a wave-based scheme for the location and quantification of damages in dams. To obtain high-resolution "interpretable" images of the damaged regions, we drew inspiration from non-linear full-multigrid methods for inverse problems and applied a new cyclic multi-stage full-waveform inversion (FWI) scheme. Our approach is less susceptible to the stability issues faced by the standard FWI scheme when dealing with ill-posed problems. In this paper, we first selected an optimal acquisition setup and then applied synthetic data to demonstrate the capability of our approach in identifying a series of anomalies in dams by a mixture of reflection and transmission tomography. The results had sufficient robustness, showing the prospects of application in the field of non-destructive testing of dams.}, subject = {Damm}, language = {en} } @phdthesis{Vogler, author = {Vogler, Verena}, title = {A framework for artificial coral reef design: Integrating computational modelling and high precision monitoring strategies for artificial coral reefs - an Ecosystem-aware design approach in times of climate change}, isbn = {978-3-00-074495-2}, doi = {10.25643/bauhaus-universitaet.4611}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220322-46115}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {243}, abstract = {Tropical coral reefs, one of the world's oldest ecosystems which support some of the highest levels of biodiversity on the planet, are currently facing an unprecedented ecological crisis during this massive human-activity-induced period of extinction. Hence, tropical reefs symbolically stand for the destructive effects of human activities on nature [4], [5]. Artificial reefs are excellent examples of how architectural design can be combined with ecosystem regeneration [6], [7], [8]. However, to work at the interface between the artificial and the complex and temporal nature of natural systems presents a challenge, i.a. in respect to the B-rep modelling legacy of computational modelling. The presented doctorate investigates strategies on how to apply digital practice to realise what is an essential bulwark to retain reefs in impossibly challenging times. Beyond the main question of integrating computational modelling and high precision monitoring strategies in artificial coral reef design, this doctorate explores techniques, methods, and linking frameworks to support future research and practice in ecology led design contexts. Considering the many existing approaches for artificial coral reefs design, one finds they often fall short in precisely understanding the relationships between architectural and ecological aspects (e.g. how a surface design and material composition can foster coral larvae settlement, or structural three-dimensionality enhance biodiversity) and lack an integrated underwater (UW) monitoring process. Such a process is necessary in order to gather knowledge about the ecosystem and make it available for design, and to learn whether artificial structures contribute to reef regeneration or rather harm the coral reef ecosystem. For the research, empirical experimental methods were applied: Algorithmic coral reef design, high precision UW monitoring, computational modelling and simulation, and validated through parallel real-world physical experimentation - two Artificial Reef Prototypes (ARPs) in Gili Trawangan, Indonesia (2012-today). Multiple discrete methods and sub techniques were developed in seventeen computational experiments and applied in a way in which many are cross valid and integrated in an overall framework that is offered as a significant contribution to the field. Other main contributions include the Ecosystem-aware design approach, Key Performance Indicators (KPIs) for coral reef design, algorithmic design and fabrication of Biorock cathodes, new high precision UW monitoring strategies, long-term real-world constructed experiments, new digital analysis methods and two new front-end web-based tools for reef design and monitoring reefs. The methodological framework is a finding of the research that has many technical components that were tested and combined in this way for the very first time. In summary, the thesis responds to the urgency and relevance in preserving marine species in tropical reefs during this massive extinction period by offering a differentiated approach towards artificial coral reefs - demonstrating the feasibility of digitally designing such 'living architecture' according to multiple context and performance parameters. It also provides an in-depth critical discussion of computational design and architecture in the context of ecosystem regeneration and Planetary Thinking. In that respect, the thesis functions as both theoretical and practical background for computational design, ecology and marine conservation - not only to foster the design of artificial coral reefs technically but also to provide essential criteria and techniques for conceiving them. Keywords: Artificial coral reefs, computational modelling, high precision underwater monitoring, ecology in design.}, subject = {Korallenriff}, language = {en} } @article{HarirchianKumariJadhavetal., author = {Harirchian, Ehsan and Kumari, Vandana and Jadhav, Kirti and Raj Das, Rohan and Rasulzade, Shahla and Lahmer, Tom}, title = {A Machine Learning Framework for Assessing Seismic Hazard Safety of Reinforced Concrete Buildings}, series = {Applied Sciences}, volume = {2020}, journal = {Applied Sciences}, number = {Volume 10, issue 20, article 7153}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app10207153}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20201022-42744}, pages = {18}, abstract = {Although averting a seismic disturbance and its physical, social, and economic disruption is practically impossible, using the advancements in computational science and numerical modeling shall equip humanity to predict its severity, understand the outcomes, and equip for post-disaster management. Many buildings exist amidst the developed metropolitan areas, which are senile and still in service. These buildings were also designed before establishing national seismic codes or without the introduction of construction regulations. In that case, risk reduction is significant for developing alternatives and designing suitable models to enhance the existing structure's performance. Such models will be able to classify risks and casualties related to possible earthquakes through emergency preparation. Thus, it is crucial to recognize structures that are susceptible to earthquake vibrations and need to be prioritized for retrofitting. However, each building's behavior under seismic actions cannot be studied through performing structural analysis, as it might be unrealistic because of the rigorous computations, long period, and substantial expenditure. Therefore, it calls for a simple, reliable, and accurate process known as Rapid Visual Screening (RVS), which serves as a primary screening platform, including an optimum number of seismic parameters and predetermined performance damage conditions for structures. In this study, the damage classification technique was studied, and the efficacy of the Machine Learning (ML) method in damage prediction via a Support Vector Machine (SVM) model was explored. The ML model is trained and tested separately on damage data from four different earthquakes, namely Ecuador, Haiti, Nepal, and South Korea. Each dataset consists of varying numbers of input data and eight performance modifiers. Based on the study and the results, the ML model using SVM classifies the given input data into the belonging classes and accomplishes the performance on hazard safety evaluation of buildings.}, subject = {Erdbeben}, language = {en} } @misc{Mukherjee, type = {Master Thesis}, author = {Mukherjee, Nilangshu}, title = {A numerical comparison of the impact of different climatic conditions in different geographic locations on the construction of an office building}, doi = {10.25643/bauhaus-universitaet.3270}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170811-32700}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {127}, abstract = {The aim of my research is to observe the variance of energy efficiency of a typical multi-story office building under the exposure of different climatic conditions. Energy efficiency requirements in building codes or energy standards are among the most important single measures for buildings' energy efficiency. Therefore, this study can be set up for a better understanding of how energy efficiency of a building changes under the effect of adverse to moderate climatic conditions which possess a mentionable effect on the operation of a building. This thesis is structured in three balanced and conceptual steps. Following the aim of the project, the virtual building model is to be analyzed under the effect of seven distinct climatic conditions namely work environment of New Delhi, Mumbai, Berlin, Lisbon, Copenhagen, Dubai and Montreal. Firstly, the task is to do a complete literature research based on the scope of similar researches and studying the problems in detail along with the theoritical background all the concepts which are implemented to get the numerical results. This chapter also comprises a detailed study of the climatic conditions of the above-mentioned cities. Different climatic traits like temperature variations, count of heating and cooling degree days, relative humidity, temperature range and comfort zonal charts for the specified cities are studied in detail. This study helps to understand the effect of these adverse to moderate climates on the operation of the building. On the second step, the virtual building model is prepared on a software platform named Revit Structures. This virtual building model is not necessarily a complete building, but it has the relevant functionalities of a real building. We perform the energy analysis and the heating and cooling analysis on this virtual building model to study the operational outcome of the building under different climatic conditions in detail. By the end of these above two tasks, two scenarios are observed. On one hand, we have a literature research and on the other hand we have the numerical results. Therefore, finally we present a comparative scenario based on the energy efficient performances of the building under such variant climatic conditions. This is followed by the prediction of thermal comfort level inside the building and it based on Fanger's PMV Model. Understanding the literature and the numerical values in detail helps us to predict the index thermal comfort level inside the building. The conclusion of this master thesis focuses mainly on the scopes of improvement of energy efficiency requirements in energy codes if any, differentiated according to specific locations. The initial aim of my hypothesis which is to study the impacts of climatic variations on the energy efficient performances of a building is fulfilled but as such topics have very deep and broad roots, the scope of further improvements is always predominant.}, subject = {Klima}, language = {en} } @phdthesis{Hollberg, author = {Hollberg, Alexander}, title = {A parametric method for building design optimization based on Life Cycle Assessment - Appendix}, series = {A parametric method for building design optimization based on Life Cycle Assessment}, journal = {A parametric method for building design optimization based on Life Cycle Assessment}, doi = {10.25643/bauhaus-universitaet.2688}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20161101-26884}, abstract = {The building sector is responsible for a large share of human environmental impacts, over which architects and planners have a major influence. The main objective of this thesis is to develop a method for environmental building design optimization based on Life Cycle Assessment (LCA) that is applicable as part of the design process. The research approach includes a thorough analysis of LCA for buildings in relation to the architectural design stages and the establishment of a requirement catalogue. The key concept of the novel method called Parametric Life Cycle Assessment(PLCA) is to combine LCA with parametric design. The application of this method to three examples shows that building designs can be optimized time-efficiently and holistically from the beginning of the most influential early design stages, an achievement which has not been possible until now.}, subject = {{\"O}kobilanz}, language = {en} } @phdthesis{MizrakBilen, author = {Mizrak Bilen, Burcin}, title = {A Power-Centered Approach to the Capitalization of Climate Change in Property Sector and Strategic Limitation}, doi = {10.25643/BAUHAUS-UNIVERSITAET.3840}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190107-38406}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {256}, abstract = {The capitalization of 'certified' sustainable building sector will be investigated over the power theory of value approach of Jonathan Nitzan and Shimshon Bichler. The study will be initiated by questioning why the environment problems are one of the first items on the agenda and by sharing the ideas of scholars who approaches the subject skeptically, because the predominant literature underlying the necessity and prominence of the topic is already well-known and adapted by the majority. Over the theory developed by Nitzan and Bichler, the concepts of capitalization, strategic sabotage, power, legitimacy, and obedience will be discussed. The hypothesis of "the absentee owners of the construction sector, holding the whip hand and capitalizing the ecology, control the growth and the creativity of green building production and make it carbon-dependent, in order to increase their profit margin" will be questioned. To strengthen the arguments in the hypothesis, the factors, the institutional arrangements, value measurement methods, which affect directly the net present value, will be investigated both in corporation and in building scale in detail, because net present value/ capitalization is asserted as the most important criteria by Nitzan and Bichler to make the investment decisions in the capitalist economic system. To trace the implications of power and the strategic sabotage that power caused, as the empirical dimension of this dissertation, an interface exploring the correlational ties between the climate responsive architecture and the ever changing political, economical, and social contexts and building economics praxis by decades will be developed and the expert interviews will be conducted with the design teams and the appraisers.}, subject = {Klima{\"a}nderung}, language = {en} } @phdthesis{Fauth, author = {Fauth, Judith}, title = {A process-oriented decision model for determining the permitability of construction projects}, doi = {10.25643/bauhaus-universitaet.4602}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220309-46020}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {325}, abstract = {In recent years, the discussion of digitalization has arrived in the media, at conferences, and in committees of the construction and real estate industry. While some areas are producing innovations and some contributors can be described as pioneers, other topics still show deficits with regard to digital transformation. The building permit process can also be counted in this category. Regardless of how architects and engineers in planning offices rely on innovative methods, building documents have so far remained in paper form in too many cases, or are printed out after electronic submission to the authority. Existing resources - for example in the form of a building information model, which could provide support in the building permit process - are not being taken advantage of. In order to use digital tools to support decision-making by the building permit authorities, it is necessary to understand the current situation and to question conditions before pursuing the overall automation of internal authority processes as the sole solution. With a substantive-organizational consideration of the relevant areas that influence building permit determination, an improvement of the building permit procedure within authorities is proposed. Complex areas - such as legal situations, the use of technology, as well as the subjective alternative action - are determined and structured. With the development of a model for the determination of building permitability, both an understanding of influencing factors is conveyed and an increase in transparency for all parties involved is created. In addition to an international literature review, an empirical study served as the research method. The empirical study was conducted in the form of qualitative expert interviews in order to determine the current state in the field of building permit procedures. The collected data material was processed and subsequently subjected to a software-supported content analysis. The results were processed, in combination with findings from the literature review, in various analyses to form the basis for a proposed model. The result of the study is a decision model that closes the gap between the current processes within the building authorities and an overall automation of the building permit review process. The model offers support to examiners and applicants in determining building permit eligibility, through its process-oriented structuring of decision-relevant facts. The theoretical model could be transferred into practice in the form of a web application.}, subject = {Baugenehmigung}, language = {en} } @phdthesis{Sowoidnich, author = {Sowoidnich, Thomas}, title = {A Study of Retarding Effects on Cement and Tricalcium Silicate Hydration induced by Superplasticizers}, isbn = {978-3-00-052204-8}, doi = {10.25643/bauhaus-universitaet.2544}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20160224-25444}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {214}, abstract = {Fließmittel werden in Betonen verwendet, um deren Fließeigenschaften w{\"a}hrend der Verarbeitung zu verbessern und Wasser einzusparen. Beide Faktoren beeinflussen nicht nur den Frischbeton, sondern auch signifikant die Festbetoneigenschaften. Nachteilig wirken sich Fließmittel auf die Festigkeitsentwicklung aus, die z.T. sehr stark verz{\"o}gert wird. Dies ist vor allem bei Bauteilen, die im Rahmen eines Vorfertigungsprozesses hergestellt werden, ein {\"o}konomischer Nachteil. Die vorliegende Arbeit widmet sich den Ursachen f{\"u}r die Verz{\"o}gerung der Portlandzementhydratation bei Verwendung von Fließmitteln. Um die komplexen Reaktionen, die w{\"a}hrend der Portlandzementhydratation auftreten, zu vereinfachen, betrachtet ein {\"u}berwiegender Teil der Arbeit die Wechselwirkung Fließmittel-Tricalciumsilikat (Abk. Ca3SiO5 oder C3S, Hauptbestandteil von Portlandzementklinker). Die Untersuchungen werden in drei Hauptteilen durchgef{\"u}hrt, wobei Methoden wie u.a. isotherme W{\"a}rmeflusskalorimetrie, Elektrische Leitf{\"a}higkeit, Elektronenmikroskopie, ICP-OES, TOC als auch Analytische Ultrazentrifugation Anwendung finden. Basierend auf der Wechselwirkung von Kationen mit anionischen Ladungstr{\"a}gern von Polymeren wird die Interaktion von Calcium mit Fließmitteln im ersten Teil der Arbeit untersucht. Dabei kommt es {\"u}berwiegend zur Komplexierung von Calciumionen durch die funktionellen Gruppen der Plymere (Carboxyl- bzw. Sulfonguppen), die in zement{\"a}ren Umgebungen sowohl gel{\"o}st in der w{\"a}ssrigen Phase als auch als Bestandteil von Partikelgrenzfl{\"a}chen vorhanden sind. Neben diesen Effekten kann auch gezeigt werden, dass Fließmittel die Bildung von nanoskaligen Partikeln hervorrufen, die infolge der sterischen Wirkung von Fließmitteln dispergiert in der w{\"a}ssrigen Phase vorliegen (Clusterbildung). Analog zu neuesten Erkenntnissen aus dem Bereich der Biomineralisation ist daher davon auszugehen, dass diese Nanopartikel durch Agglomeration das Kristallwachtsum beeinflussen. Ausgehend von der Annahme, dass die Aufl{\"o}sungs- und/ oder F{\"a}llungskinetik durch die Wirkung von Fließmitteln behindert und damit f{\"u}r den Verz{\"o}gerungseffekt der Fließmittel w{\"a}hrend der komplexen Hydratationsreaktion verantwortlich seien k{\"o}nnen, werden die zugrundeliegenden Vorg{\"a}nge im zweiten Abschnitt getrennt voneinander untersucht. Es wird anhand von L{\"o}sungsuntersuchungen an C-S-H Phasen und Portlandit herausgestellt, dass die Komplexierung von gel{\"o}sten Calciumionen durch funktionelle Gruppen der Polymere die L{\"o}slichkeit von Portlandit erh{\"o}ht. Im Gegensatz f{\"u}hrt die Komplexierung von Calciumionen in der w{\"a}ssrigen Phase zu einer Verringerung der Calciumionenkonzentration in der w{\"a}ssrigen Phase. Diese Effekte werden auf die unterschiedlich starke Adsorptionsneigung der Polymere an C-S-H-Phasen und Portlandit zur{\"u}ckgef{\"u}hrt. Es wird davon ausgegangen, dass die Adsorption aufgrund der gr{\"o}ßeren spezifischen Oberfl{\"a}che st{\"a}rker an den C-S-H-Phasen als am Portlandit auftritt. Demnach stellt sich dar, dass die Polymere erst nachdem die funktionellen Gruppen Calciumionen aus der w{\"a}ssrigen Phase komplexiert haben an den C-S-H-Phasen adsorbieren. Weiterhin kann gezeigt werden, dass die freie C3S Aufl{\"o}sungsrate in Anwesenheit von Fließmitteln keinen direkten Zusammenhang zur Verz{\"o}gerung erkennen l{\"a}sst. Teilweise kommt es zu einer in Bezug zur Kontrollprobe ohne Fließmittel erh{\"o}hten sowie auch verringerten Aufl{\"o}sungsrate. Wird das Komplexierungsvem{\"o}gen der Fließmittel ber{\"u}cksichtigt, so kann durchaus eine verlangsamte freie Aufl{\"o}sungsrate ermittelt werden. Doch auch Calcit zeigt einen verz{\"o}gernden Einfluss auf die freie C3S Aufl{\"o}sung, obwohl es den Gesamtprozess der Hydratation signifikant beschleunigt. Somit kann die behinderte Aufl{\"o}sung als m{\"o}gliche Ursache f{\"u}r die verz{\"o}gernde Wirkung w{\"a}hrend der Zementhydratation weder best{\"a}tigt noch widerlegt werden. Dieser Punkt sollte in zuk{\"u}nftigen Arbeiten weiter untersucht werden. Im letzten Schritt dieses Untersuchungsabschnitts wird die reine Kristallisation von C-S-H-Phasen und Portlandit untersucht. Es stellt sich heraus, dass Fließmittel insbesondere durch die Wirkung der Komplexierung von Ionen in der w{\"a}ssrigen Phase sowohl die Induktionszeit verl{\"a}ngern als auch die Kristallwachstumsrate ver{\"a}ndern. Dies allein kann aber nicht die komplette Verz{\"o}gerungswirkung erkl{\"a}ren. Ein wichtiger Verz{\"o}gerungsfaktor ist die Adsorption der Polymere an Kristalloberfl{\"a}chen als auch eine fließmittelbedingte Dispergierung von nanoskaligen Einzelpartikeln, die deren Agglomeration zu Kristallen behindert. Im letzten Hauptuntersuchungsabschnitt werden die gewonnenen Erkenntnisse auf die w{\"a}hrend der Zement- und Tricalciumsilikathydratation parallel ablaufenden Reaktionen analysiert. Dabei wird insbesondere die ionische Zusammensetzung der w{\"a}ssrigen Phase von C3S Pasten und Suspensionen untersucht, um Hinweise f{\"u}r eine kinetische Hemmung der Hydratationsreaktion zu identifizieren. Zusammenfassend wird festgestellt, dass die Ursachen der verz{\"o}gernden Wirkung von Fließmitteln auf die Hydratation von C3S auf die starke Verz{\"o}gerung der Kristallisation von Hydratphasen zur{\"u}ckzuf{\"u}hren ist. Dabei kommt den zwei Faktoren Komplexierung von Calciumionen an Oberfl{\"a}chen und Stabilisierung von nanoskaligen Partikeln eine zentrale Bedeutung zu. Diese Effekte k{\"o}nnen durch die Wirkung als Templat als auch durch Erh{\"o}hung der L{\"o}slichkeit infolge Komplexierung freier/gel{\"o}ster Ionen teilkompensiert werden. Dass die Aufl{\"o}sungsreaktion durch die Anwesenheit von Fließmitteln behindert wird, kann nur indirekt anhand der Entwicklung von Ionenkonzentrationen festgestellt werden. Ob dieser Vorgang die Ursache oder die Folge des L{\"o}sungs-F{\"a}llungs-Mechanismus der Hydratation ist und damit die verz{\"o}gernde Wirkung durch behinderte Aufl{\"o}sung des Edukts hervorgerufen wird, bleibt Gegenstand weiterer Untersuchungen. Im Rahmen der Arbeit kann auch gezeigt werden, dass Fließmittel chemisch als Inhibitoren wirken indem sie den Frequenzfaktor verringern. Dar{\"u}ber hinaus wird erstmalig eine Methode entwickelt, die die Bestimmung der Ionenkonzentration in Pasten in-situ erlaubt. Mit deren Hilfe wird dargestellt, dass die Entwicklung der Ionenkonzentration als auch die allgemein verwendete W{\"a}rmefreisetzungsrate (Kalorimetrie) miteinander korrespondiert. Dar{\"u}ber hinaus erlaubt die entwickelte Methode die weitere Differenzierung der Accelerationsperiode in drei Stadien. Die Kristallisation von C-S-H-Phasen und Portlandit ist f{\"u}r den Beginn der Haupthydratationsperiode entscheidend.}, subject = {Cement}, language = {en} }