Pumping is the most efficient transportation and placing method for concrete. Despite the immense progress in the field of concrete technology in the last years, so far there are still neither official regulations nor verified theoretical foundations to be used for the assessment and accurate prediction pumping behaviour of ordinary and high performance concretes. This thesis aims at purposefully investigating pumping of modern concretes and bridging the existing knowledge gap. The main achievement of the present research is the development and verification of a sitecompliant and scientifically based methodology for characterisation and prediction of fresh concrete pumping behaviour. The research focus is set on the importance of the forming lubricating layer (LL) during pumping. Within an extended experimental program, the properties of the LL are captured and quantified. They determine the reduction of friction at the pipe wallconcrete interface and thereby govern the concrete flow. It is proven that the composition and the rheological properties of the forming LL exert an enormous impact on pumping since most of the induced shear stress by pumping pressure is concentrated in this layer. In a further step, the flow pattern of concrete is analytically and numerically determined. The concrete exhibits various principal flow types which are already defined at low flow rates: plug flow in case of strainhardening cementbased composite (SHCC), partial concrete bulk shear in ordinary concretes and pronounced bulk shear for selfcompacting concrete (SCC). The results from the fullscale pumping campaign are confronted with the existing pressure performance nomogram on the determination of pumping parameters. The nomogram’s prediction capacity is extended and verified for highly flowable concretes by replacing the slump and flow table results with the viscosity parameter of the LL. Furthermore, the challenges during pumping of concrete, inter alia, priming of the pipeline, blockage formation and final cleaning, are exemplified, and recommendations for the practitioners are provided. Finally, the transfer of the developed scientifically based and ready to use methodology on site is strongly advocated as a part of the future in situ rheology monitoring concept towards envisaged full automation of concrete production and casting processes. / Das Pumpen stellt die effektivste Methode für das Fördern und Einbringen von Frischbeton auf der Baustelle dar. Trotz der in den letzten Jahren erreichten deutlichen Fortschritte auf betontechnologischem Gebiet existieren für die Beurteilung der Pumpbarkeit von Beton bisher weder offiziell gültige Vorschriften noch abgesicherte theoretische Grundlagen, die eine zielsichere Vorhersage des Pumpverhaltens von Normal- als auch Hochleistungsbetonen ermöglichen. Die vorliegende Arbeit schließt entsprechende Wissenslücken und befasst sich gezielt mit dem Pumpen moderner Betone. Grundlegenden Erkenntnisgewinn stellt die Entwicklung einer wissenschaftlich fundierten, baustellengerechten Prüfmethodik zur Charakterisierung und Vorhersage des Pumpverhaltens von Frischbeton dar. Der Untersuchungsfokus richtet sich auf die Wirkung der sich beim Pumpvorgang ausbildenden Gleitschicht. Ein umfangreiches Untersuchungsprogramm gestattet die Erfassung und Quantifizierung der Eigenschaften dieser Schicht. Sie bestimmen infolge deutlicher Reduzierung der Reibung an der Grenzfläche zwischen Rohrwandung und Beton die Betonströmung entscheidend. Bewiesen wird, dass Betonzusammensetzung und rheologische Eigenschaften der Gleitschicht maßgebende Auswirkungen auf den Pumpvorgang haben, da sich die pumpdruckinduzierte Scherspannung in dieser Schicht konzentriert. Weiterhin erfolgt sowohl eine analytische als auch numerische Charakterisierung der Betonströmung im Rohr. Nachgewiesen wird, dass sich beim Pumpvorgang betonspezifisch unterschiedliche Strömungsarten einstellen, die bereits bei niedrigen Durchflussmengen definiert sind: Pfropfenströmung in hochduktilen Betonen, partielle Scherung des Kernbetons in Normalbetonen und signifikante Scherung in selbstverdichtenden Betonen. Aus großtechnisch durchgeführten Pumpversuchen gewonnene Ergebnisse werden dem derzeit vorhandenen, verbesserungsbedürftigen Betondruck-Leistungs-Nomogramm zur Einstellung von Parametern an der Betonpumpe gegenübergestellt. Die Vorhersagekapazität des Nomogramms kann durch den Ersatz der Ausbreit- bzw. Setzfließmaßangaben mit Viskositätsangaben der Gleitschicht erweitert und verifiziert werden. Des Weiteren werden baustellenbezogene Herausforderungen im Gesamtprozess des Betonpumpvorgangs, u. a. Vorbereitung der Rohrleitung vor dem Pumpen, Auftreten von Stopfern und Endreinigung exemplarisch dargestellt sowie Empfehlungen für die Praktiker erarbeitet. Schließlich wird der Transfer der in dieser Arbeit entwickelten wissenschaftlich basierten und anwendungsbereiten Methodik als Teil des zukünftigen Konzeptes für die in-situ Rheologie-Überwachung hinsichtlich einer angestrebten vollständigen Automatisierung von Fertigungs- und Einbringprozessen von Beton mit Nachdruck empfohlen.

Reducing the energy consumption of off-highway machinery due to poor system efficiency is an urgent challenge. Several advanced and innovative architectures have been proposed over the years to tackle this problem, but very few of them found fertile ground for commercial applications due to increased complexity and cost. In this paper, the design, implementation, and testing of a multi-service Digital Displacement ® Pump architecture applied to an excavator are presented. The Digital Displacement ® Pump allows for a dynamic physical displacement allocation to services at different pressure levels, thus reducing throttling losses required to operate multiple actuators simultaneously. A feed-forward control logic is implemented and applied to the system using a closed-centre architecture. The results indicate a fuel reduction of more than 30% compared to the baseline excavator.

Imagine a system with a pump driven by a speed-controlled electric motor. What and how much can be gained by using a pump with discretely variable displacement instead of a conventional fixed pump in such a system? This question is the focus in this paper, in which a simulation study based on a drive cycle for a loader crane is presented. The results indicate that the system efficiency from inverter input to pump output can increase by a few percentages. This might be considered small in relation to the increasing complexity that comes with discrete displacement. However, the results also show that a system with discrete displacement substantially reduces torque and cooling requirements on the electric motor. The required maximum torque can be reduced by 30 to 50 % and the motor can generate up to 40 % less heat since it can work in more efficient conditions. These potential benefits will be obtained with only a few discrete displacement settings available.

The correlation between concrete rheological parameters and its pumping behavior under consideration of the so-called lubricating layer has been investigated for decades. In this thesis, flow-induced particle migration (FIPM) was studied in-depth, as the main underlying mechanism for the formation of the lubricating layer. Conventionally vibrated and self-compacting concretes were chosen as the target mixtures. Furthermore, cementitious model concretes, containing colored glass beads, were proposed to obtain further insights into the FIPM and its impact on pumping. The mixtures were differentiating with regard to particle volume fractions, mortars composition, maximum particle size and particle size distributions. In the experiments, various established methods were used to characterize the rheological properties and the pumping behavior of the concretes. New methodologies for estimating the thickness of the lubricating layer and the particle distribution in pumped cross-sections were proposed as well. The rheological properties and pumping behavior of real and model concretes were in agreement with the state-of-the-art literature. Based on the radial particle distributions, it was illustrated that the particle migration intensifies by increasing the particle size and decreasing the total volume fraction of solid particles. Furthermore, in highly-concentrated poly-dispersed model concretes, the particle concentration curves consist of a sudden jump close to the pipe wall and a relatively uniform distribution in the inner zone of the pipe. In these cases, the influence of FIPM on overall flow behavior cannot be neglected. Moreover, it was shown that the lubricating layer thickness is not constant for all concrete mixtures. For poly-dispersed suspensions, the shear-induced particle migration (SIPM) has a stronger impact than the wall for forming the lubricating layer. Finally, it was concluded that a solid-liquid threshold of 1 to 2 mm is a reliable choice when investigating concrete pipe flow. The faster the concrete is pumped or the lower the yield stress of the constitutive mortar is, the smaller is the solid-liquid threshold. Based on the experimental findings, a first-order physical correlation between pumping parameters (pressure and discharge rate), particle properties (volume fraction and packing properties) and lubricating layer properties (thickness and viscosity) was proposed. Accordingly, for a simple flow topology with a shearing lubricating layer and an extruding yield stress concrete, the lubricating layer thickness was computed from the competition between shear-induced fluxes of particles. In agreement with the driving equations of SIPM, it was assumed that the first flux correlates with the internal stress gradient in the plug concrete whereas the counteracting particle flux correlates with the shear rate in the lubricating layer. The model was validated for two flow types, pipe flow in the Sliper and Couette flow in a co-axial tribometer. The proposed model can capture the observed main features and their evolutions despite the absence of any fitting parameters.

Numerous recurrent situations following mixing and pumping of mortars and concretes cause degradation of fluidity and hardening characteristics. Which, in turn, lead to adverse effects on the quality of workmanship and structural defects. Nonetheless, relatively little research on the mixing and pumping energies used for the onsite transport and preparation of mortar or concrete has been directed at the core reasons or mechanisms for changes in technological properties. This dissertation describes and explains the effects of various mixing and pumping parameters on the mortar characteristics in a field trial and on a laboratory scale. Observations using a rheograph revealed that shearing action does exhibit the most pronounced influence on the characteristics of mortars during the pumping. The performed investigations indicate that higher shearing actions, for example, excessive mixing duration and long-distance pumping lead to reduced flowability, accelerated and increased hydration rate, increased early compressive strength and early-age shrinkage. From these findings, the underlying mechanism responsible for acceleration and increase of hydration rate is pinpointed as: the increased dissolution from the active surface area due to the destruction of the protective superficial layers of cement grains, as well as a transition from flocculation to dispersion. The creation of new surfaces leads to further consumption of active super plasticizer in solution phase and to subsequent degrading changes in fluidity (decreasing flowability). The degradation of fluidity and densification of microstructure provoked by the hydration changes do increase the early age shrinkage of mortar.

Oil lubrication film plays an important role in analysis of dynamic behavior of the internal gear motors and pumps. During operation, the oil film is considered as the spring and damping system. Therefore, calculation of the dynamic stiffness and damping coefficients is necessary to build the mathematical model for studying of dynamic problem. In order to calculate these coefficients, the dynamic pressure and perturbing pressure distribution must be determined firstly. In this paper, the infinitesimal perturbation method (IFP) is used to calculate the dynamic pressure distribution. Based on that the dynamic stiffness and damping coefficients can be computed. The calculation results point out that the dynamic stiffness and damping coefficients are much dependent on the eccentricity ratio.

The following article describes the development, validation and series introduction of a novel highly integrated smart electrohydraulic 4-quadrant displacement machine. Starting in 2012, an unique unit consisting of a hydraulic internal gear machine combined with a newly developed electric machine with integrated electronic unit was created. The developed unit aims at the application in fully active automotive chassis in combination with hydraulic shock absorbers. The very special requirements of this application resulted in a new development with numerous detailed solutions which are described below. Parallel and interacting with the product development, all new series assembly and testing devices tailored to this product was developed.

Getriebener Transport wechselwirkender Teilchen ist im direkten oder übertragenen Sinne von großer Bedeutung für viele Forschungsfelder. Zur Untersuchung grundlegender Fragestellungen wird auf einfache Modellsysteme zurückgegriffen, die analytische Zugänge ermöglichen und zugleich wesentliche Aspekte der Nichtgleichgewichtsdynamik in realen Applikationen erfassen. Im ersten Teil dieser Arbeit wird ein eindimensionales Gittergas mit Nächsten-Nachbar-Wechselwirkungen betrachtet, um den Einfluss von Wechselwirkungen auf den Teilchentransport in getriebenen Diffusionsprozessen zu studieren. Mit einem auf der zeitabhängigen Dichtefunktionaltheorie klassischer Fluide basierenden Verfahren werden Evolutionsgleichungen für Dichten, Korrelationsfunktionen und Ströme aufgestellt, deren numerische Lösung eine gute Beschreibung der Transportkinetik liefert. Für Sprungdynamiken, welche bestimmte Relationen erfüllen, werden exakte Strom-Dichte-Beziehungen in geschlossenen Ringsystemen hergeleitet. Hierzu zählen insbesondere die für viele Applikationen relevanten Glauber-Raten. In offenen Kanälen, die zwei Reservoire verbinden, kommt es zu Phasenübergängen der Teilchendichte im Inneren des Kanals. Anhand allgemeiner Überlegungen auf Grundlage der Extremalprinzipien bezüglich des Stroms und der Strom-Dichte-Relation im Bulk kann ein Überblick aller möglichen Phasen, ungeachtet der konkreten System-Reservoir-Kopplung, erhalten werden. Welche Phasen im randinduzierten Phasendiagramm erscheinen, wird durch die System-Reservoir-Kopplung festgelegt. Dies wird anhand zweier unterschiedlicher Randankopplungen demonstriert. Im zweiten Teil der Dissertationsschrift werden stochastische Transportvorgänge in Brownschen Pumpen und in organischen Solarzellen mit Heteroübergang modelliert. Hierbei zeigen Brownsche Pumpen Phasenübergänge in periodengemittelten Dichten und Strömen, falls Ausschlusswechselwirkungen berücksichtigt werden. Ein Minimalmodell organischer Solarzellen erlaubt Elementarprozesse an der Donator-Akzeptor-Grenzfläche abzubilden, wodurch Einblicke in das Strom- und Effizienzverhalten des photovoltaischen Systems gewonnen werden.

Pumping is the most efficient transportation and placing method for concrete. Despite the immense progress in the field of concrete technology in the last years, so far there are still neither official regulations nor verified theoretical foundations to be used for the assessment and accurate prediction pumping behaviour of ordinary and high performance concretes. This thesis aims at purposefully investigating pumping of modern concretes and bridging the existing knowledge gap. The main achievement of the present research is the development and verification of a sitecompliant and scientifically based methodology for characterisation and prediction of fresh concrete pumping behaviour. The research focus is set on the importance of the forming lubricating layer (LL) during pumping. Within an extended experimental program, the properties of the LL are captured and quantified. They determine the reduction of friction at the pipe wallconcrete interface and thereby govern the concrete flow. It is proven that the composition and the rheological properties of the forming LL exert an enormous impact on pumping since most of the induced shear stress by pumping pressure is concentrated in this layer. In a further step, the flow pattern of concrete is analytically and numerically determined. The concrete exhibits various principal flow types which are already defined at low flow rates: plug flow in case of strainhardening cementbased composite (SHCC), partial concrete bulk shear in ordinary concretes and pronounced bulk shear for selfcompacting concrete (SCC). The results from the fullscale pumping campaign are confronted with the existing pressure performance nomogram on the determination of pumping parameters. The nomogram’s prediction capacity is extended and verified for highly flowable concretes by replacing the slump and flow table results with the viscosity parameter of the LL. Furthermore, the challenges during pumping of concrete, inter alia, priming of the pipeline, blockage formation and final cleaning, are exemplified, and recommendations for the practitioners are provided. Finally, the transfer of the developed scientifically based and ready to use methodology on site is strongly advocated as a part of the future in situ rheology monitoring concept towards envisaged full automation of concrete production and casting processes.:ZUSAMMENFASSUNG V ABSTRACT VII VORWORT DES HERAUSGEBERS IX DANKSAGUNG XI SYMBOLS XVII INTRODUCTION 1 1.1 FLASHLIGHTS ON HISTORY 1 1.2 MOTIVATION 1 1.3 RESEARCH FIELD 3 1.4 RESEARCH CONCEPT 6 1.5 ECONOMIC RELEVANCE 8 1.6 STRUCTURE AND BOUNDARIES OF THE THESIS 10 STATE OF THE ART 13 2.1 GENERAL 13 2.2 CONCRETE FLOW IN PIPELINE 13 2.3 INFLUENCE OF CONCRETE RHEOLOGY ON PUMPING BEHAVIOUR 16 2.3.1 CEMENT HYDRATION 16 2.3.2 MIXTURE COMPOSITION 17 2.3.2.1 WATER-TO-BINDER RATIO AND PASTE VOLUME 18 2.3.2.2 AGGREGATES 20 2.3.2.3 ADMIXTURES AS PUMPING AIDS 22 2.3.3 HYDRODYNAMIC INTERACTIONS 25 2.3.4 SHEAR HISTORY 27 2.3.5 TEMPERATURE 28 2.4 FORMATION OF LUBRICATING LAYER 30 2.4.1 FLOW-INDUCED PARTICLE MIGRATION 30 2.4.2 PROPERTIES 31 2.4.3 EXPERIMENTAL CHARACTERISATION 32 2.5 BOUNDARY CONDITIONS 32 2.6 PUMPING EQUIPMENT 34 2.7 PRIMING 35 3 APPLIED METHODS 37 3.1 GENERAL 37 3.2 RHEOMETRY 37 3.3 DIRECT DETERMINATION OF PUMPING PRESSURE 40 3.4 SAMPLING AND PRODUCTION OF LUBRICATING MATERIAL 42 3.5 MEASUREMENT OF FILTRATE AMOUNT 45 3.6 ANALYTICAL DETERMINATION OF LUBRICATING LAYER THICKNESS 47 3.7 SMALL-SCALE PUMPING 49 3.8 FULL-SCALE PUMPING 50 3.9 NUMERICAL METHOD 56 3.9.1 MATERIAL MODEL 56 3.9.2 NUMERICAL IMPLEMENTATION 58 4 CHARACTERISATION OF CONCRETE PUMPABILITY 63 4.1 GENERAL 63 4.2 MIXTURE DESIGN PARAMETERS 63 4.3 COMPARISON BETWEEN REFERENCE AND DESIGN MORTARS 65 4.4 RESULTS AND DISCUSSION 65 4.4.1 RHEOLOGICAL BEHAVIOUR OF CONCRETES AND DESIGN MORTARS 65 4.4.2 INFLUENCE OF WALL ROUGHNESS ON RHEOLOGICAL PARAMETERS 67 4.4.3 PREDICTION OF PUMPING PRESSURE 72 4.5 SUMMARY 74 5 LUBRICATING LAYER THICKNESS AND CONCRETE FLOW 75 5.1 GENERAL 75 5.2 MIXTURE DESIGN PARAMETERS 75 5.3 RESULTS AND DISCUSSION 76 5.3.1 CONCRETE FLOW TYPE 76 5.3.2 PREDICTION AND VERIFICATION OF PUMPING PRESSURE 77 5.3.3 QUANTIFICATION OF LUBRICATING LAYER THICKNESS 79 5.4 SUMMARY 82 6 FULL-SCALE PUMPING EXPERIMENTS 83 6.1 GENERAL 83 6.2 MIXTURES AND DESIGN PARAMETERS 83 6.3 RESULTS AND DISCUSSION 85 6.3.1 PRESSURE LOSS AND PRESSURE-FLOW RATE CURVES 85 6.3.2 NUMERICAL SIMULATION RESULTS 86 6.3.3 PRESSURE PREDICTION USING MODIFIED NOMOGRAM 88 6.3.4 COMPARISON BETWEEN PREDICTED AND ACTUAL PRESSURE-FLOW RATE CURVES 90 6.4 SUMMARY 92 7 EFFECT OF PUMPING ON FRESH PROPERTIES OF CONCRETE AND FILTRATE FORMATION 95 7.1 GENERAL 95 7.2 MIXTURES DESIGN PARAMETERS 95 7.3 INFLUENCE OF PUMPING ON PROPERTIES OF FRESH CONCRETE 97 7.4 INFLUENCE OF CONCRETE PROPERTIES ON KINETICS OF FILTRATE FORMATION 98 7.5 IMPACT OF FILTRATE AMOUNT ON PUMPABILITY 101 7.6 SUMMARY 104 8 CHALLENGES RELATED TO PUMPING OF CONCRETE 105 8.1 GENERAL 105 8.2 PRIMING GROUT 105 8.3 PIPELINE GEOMETRY 108 8.4 BLOCKAGES 113 8.5 FILLING DEGREE OF PUMP PISTONS 116 8.6 TEMPERATURE CONTROL 117 8.7 VERTICAL PUMPING 118 8.8 CLEANING THE PIPELINE 119 8.9 SUMMARY 120 9 FINAL CONCLUSIONS AND OUTLOOK 121 9.1 GENERAL 121 9.2 CONCRETE FLOW TYPE 121 9.3 LUBRICATING LAYER PROPERTIES 121 9.4 RHEOLOGICAL DEVICES 122 9.5 FILTRATE FORMATION 122 9.6 NUMERICAL SIMULATIONS 122 9.7 MODIFIED NOMOGRAM 123 9.8 RELEVANCE OF PUMPING EXPERIMENTS 123 9.9 INFLUENCE OF PUMPING ON FRESH CONCRETE PROPERTIES 124 9.10 GENERATED DATABASE 124 9.11 IMPROVING NUMERICAL MODEL 124 9.12 TODAY AND TOMORROW 124 BIBLIOGRAPHY 127 APPENDIX A 135 A.1 MATERIALS DESCRIPTION, CHAPTERS 4 AND 5 135 A.2 MATERIALS DESCRIPTION, CHAPTERS 6, 7 AND 8 136 APPENDIX B 137 APPENDIX C 141 LIST OF SELECTED PUBLICATIONS 143 JOURNALS 143 CONFERENCE PAPERS 143 CURRICULUM VITAE 145 / Das Pumpen stellt die effektivste Methode für das Fördern und Einbringen von Frischbeton auf der Baustelle dar. Trotz der in den letzten Jahren erreichten deutlichen Fortschritte auf betontechnologischem Gebiet existieren für die Beurteilung der Pumpbarkeit von Beton bisher weder offiziell gültige Vorschriften noch abgesicherte theoretische Grundlagen, die eine zielsichere Vorhersage des Pumpverhaltens von Normal- als auch Hochleistungsbetonen ermöglichen. Die vorliegende Arbeit schließt entsprechende Wissenslücken und befasst sich gezielt mit dem Pumpen moderner Betone. Grundlegenden Erkenntnisgewinn stellt die Entwicklung einer wissenschaftlich fundierten, baustellengerechten Prüfmethodik zur Charakterisierung und Vorhersage des Pumpverhaltens von Frischbeton dar. Der Untersuchungsfokus richtet sich auf die Wirkung der sich beim Pumpvorgang ausbildenden Gleitschicht. Ein umfangreiches Untersuchungsprogramm gestattet die Erfassung und Quantifizierung der Eigenschaften dieser Schicht. Sie bestimmen infolge deutlicher Reduzierung der Reibung an der Grenzfläche zwischen Rohrwandung und Beton die Betonströmung entscheidend. Bewiesen wird, dass Betonzusammensetzung und rheologische Eigenschaften der Gleitschicht maßgebende Auswirkungen auf den Pumpvorgang haben, da sich die pumpdruckinduzierte Scherspannung in dieser Schicht konzentriert. Weiterhin erfolgt sowohl eine analytische als auch numerische Charakterisierung der Betonströmung im Rohr. Nachgewiesen wird, dass sich beim Pumpvorgang betonspezifisch unterschiedliche Strömungsarten einstellen, die bereits bei niedrigen Durchflussmengen definiert sind: Pfropfenströmung in hochduktilen Betonen, partielle Scherung des Kernbetons in Normalbetonen und signifikante Scherung in selbstverdichtenden Betonen. Aus großtechnisch durchgeführten Pumpversuchen gewonnene Ergebnisse werden dem derzeit vorhandenen, verbesserungsbedürftigen Betondruck-Leistungs-Nomogramm zur Einstellung von Parametern an der Betonpumpe gegenübergestellt. Die Vorhersagekapazität des Nomogramms kann durch den Ersatz der Ausbreit- bzw. Setzfließmaßangaben mit Viskositätsangaben der Gleitschicht erweitert und verifiziert werden. Des Weiteren werden baustellenbezogene Herausforderungen im Gesamtprozess des Betonpumpvorgangs, u. a. Vorbereitung der Rohrleitung vor dem Pumpen, Auftreten von Stopfern und Endreinigung exemplarisch dargestellt sowie Empfehlungen für die Praktiker erarbeitet. Schließlich wird der Transfer der in dieser Arbeit entwickelten wissenschaftlich basierten und anwendungsbereiten Methodik als Teil des zukünftigen Konzeptes für die in-situ Rheologie-Überwachung hinsichtlich einer angestrebten vollständigen Automatisierung von Fertigungs- und Einbringprozessen von Beton mit Nachdruck empfohlen.:ZUSAMMENFASSUNG V ABSTRACT VII VORWORT DES HERAUSGEBERS IX DANKSAGUNG XI SYMBOLS XVII INTRODUCTION 1 1.1 FLASHLIGHTS ON HISTORY 1 1.2 MOTIVATION 1 1.3 RESEARCH FIELD 3 1.4 RESEARCH CONCEPT 6 1.5 ECONOMIC RELEVANCE 8 1.6 STRUCTURE AND BOUNDARIES OF THE THESIS 10 STATE OF THE ART 13 2.1 GENERAL 13 2.2 CONCRETE FLOW IN PIPELINE 13 2.3 INFLUENCE OF CONCRETE RHEOLOGY ON PUMPING BEHAVIOUR 16 2.3.1 CEMENT HYDRATION 16 2.3.2 MIXTURE COMPOSITION 17 2.3.2.1 WATER-TO-BINDER RATIO AND PASTE VOLUME 18 2.3.2.2 AGGREGATES 20 2.3.2.3 ADMIXTURES AS PUMPING AIDS 22 2.3.3 HYDRODYNAMIC INTERACTIONS 25 2.3.4 SHEAR HISTORY 27 2.3.5 TEMPERATURE 28 2.4 FORMATION OF LUBRICATING LAYER 30 2.4.1 FLOW-INDUCED PARTICLE MIGRATION 30 2.4.2 PROPERTIES 31 2.4.3 EXPERIMENTAL CHARACTERISATION 32 2.5 BOUNDARY CONDITIONS 32 2.6 PUMPING EQUIPMENT 34 2.7 PRIMING 35 3 APPLIED METHODS 37 3.1 GENERAL 37 3.2 RHEOMETRY 37 3.3 DIRECT DETERMINATION OF PUMPING PRESSURE 40 3.4 SAMPLING AND PRODUCTION OF LUBRICATING MATERIAL 42 3.5 MEASUREMENT OF FILTRATE AMOUNT 45 3.6 ANALYTICAL DETERMINATION OF LUBRICATING LAYER THICKNESS 47 3.7 SMALL-SCALE PUMPING 49 3.8 FULL-SCALE PUMPING 50 3.9 NUMERICAL METHOD 56 3.9.1 MATERIAL MODEL 56 3.9.2 NUMERICAL IMPLEMENTATION 58 4 CHARACTERISATION OF CONCRETE PUMPABILITY 63 4.1 GENERAL 63 4.2 MIXTURE DESIGN PARAMETERS 63 4.3 COMPARISON BETWEEN REFERENCE AND DESIGN MORTARS 65 4.4 RESULTS AND DISCUSSION 65 4.4.1 RHEOLOGICAL BEHAVIOUR OF CONCRETES AND DESIGN MORTARS 65 4.4.2 INFLUENCE OF WALL ROUGHNESS ON RHEOLOGICAL PARAMETERS 67 4.4.3 PREDICTION OF PUMPING PRESSURE 72 4.5 SUMMARY 74 5 LUBRICATING LAYER THICKNESS AND CONCRETE FLOW 75 5.1 GENERAL 75 5.2 MIXTURE DESIGN PARAMETERS 75 5.3 RESULTS AND DISCUSSION 76 5.3.1 CONCRETE FLOW TYPE 76 5.3.2 PREDICTION AND VERIFICATION OF PUMPING PRESSURE 77 5.3.3 QUANTIFICATION OF LUBRICATING LAYER THICKNESS 79 5.4 SUMMARY 82 6 FULL-SCALE PUMPING EXPERIMENTS 83 6.1 GENERAL 83 6.2 MIXTURES AND DESIGN PARAMETERS 83 6.3 RESULTS AND DISCUSSION 85 6.3.1 PRESSURE LOSS AND PRESSURE-FLOW RATE CURVES 85 6.3.2 NUMERICAL SIMULATION RESULTS 86 6.3.3 PRESSURE PREDICTION USING MODIFIED NOMOGRAM 88 6.3.4 COMPARISON BETWEEN PREDICTED AND ACTUAL PRESSURE-FLOW RATE CURVES 90 6.4 SUMMARY 92 7 EFFECT OF PUMPING ON FRESH PROPERTIES OF CONCRETE AND FILTRATE FORMATION 95 7.1 GENERAL 95 7.2 MIXTURES DESIGN PARAMETERS 95 7.3 INFLUENCE OF PUMPING ON PROPERTIES OF FRESH CONCRETE 97 7.4 INFLUENCE OF CONCRETE PROPERTIES ON KINETICS OF FILTRATE FORMATION 98 7.5 IMPACT OF FILTRATE AMOUNT ON PUMPABILITY 101 7.6 SUMMARY 104 8 CHALLENGES RELATED TO PUMPING OF CONCRETE 105 8.1 GENERAL 105 8.2 PRIMING GROUT 105 8.3 PIPELINE GEOMETRY 108 8.4 BLOCKAGES 113 8.5 FILLING DEGREE OF PUMP PISTONS 116 8.6 TEMPERATURE CONTROL 117 8.7 VERTICAL PUMPING 118 8.8 CLEANING THE PIPELINE 119 8.9 SUMMARY 120 9 FINAL CONCLUSIONS AND OUTLOOK 121 9.1 GENERAL 121 9.2 CONCRETE FLOW TYPE 121 9.3 LUBRICATING LAYER PROPERTIES 121 9.4 RHEOLOGICAL DEVICES 122 9.5 FILTRATE FORMATION 122 9.6 NUMERICAL SIMULATIONS 122 9.7 MODIFIED NOMOGRAM 123 9.8 RELEVANCE OF PUMPING EXPERIMENTS 123 9.9 INFLUENCE OF PUMPING ON FRESH CONCRETE PROPERTIES 124 9.10 GENERATED DATABASE 124 9.11 IMPROVING NUMERICAL MODEL 124 9.12 TODAY AND TOMORROW 124 BIBLIOGRAPHY 127 APPENDIX A 135 A.1 MATERIALS DESCRIPTION, CHAPTERS 4 AND 5 135 A.2 MATERIALS DESCRIPTION, CHAPTERS 6, 7 AND 8 136 APPENDIX B 137 APPENDIX C 141 LIST OF SELECTED PUBLICATIONS 143 JOURNALS 143 CONFERENCE PAPERS 143 CURRICULUM VITAE 145

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group A: Materials Group B: System design & integration Group C: Novel system solutions Group D: Additive manufacturing Group E: Components Group F: Intelligent control Group G: Fluids Group H | K: Pumps Group I | L: Mobile applications Group J: Fundamentals