TY - CONF A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten T1 - Entwicklung eines selbstverdichtenden Betons mit inerten Zusatzstoffen-Prüfung nach europäischer Richtlinie für SVB N2 - Im Rahmen von MICROCON, einem europäischen CRAFT-Projekt, besteht eine wesentliche Zielsetzung in der Optimierung von selbstverdichtendem Beton (SVB) im Hinblick auf Kosten und Leistungsfähigkeit durch den Einsatz von teilweise puzzolanischen Microfillern. Um die Puzzolanität bei der Beurteilung besser bewerten zu können, wird ein Referenzbeton benötigt, der aus weitestgehend inerten Zusatzstoffen besteht. Die Entwicklung eines solchen Referenzbetons fand an der BAM nach der japanischen Methode nach Okamura statt. T2 - Wissenschaftsrat CY - Berlin, Germany DA - 17.02.2006 PY - 2006 AN - OPUS4-12030 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Uzoegbo, H.C. A1 - Priebe, Nsesheye Susan A1 - Kühne, Hans-Carsten A1 - Rogge, Andreas ED - Uzoegbo, H.C. ED - Schmidt, Wolfram T1 - Experiences in an African-European-cooperation project: strengthening research capacity in cement and concrete in Africa N2 - This report is based on a three-year experience as coordinator of the ACP-EU funded SPIN project. The project involved eight African and three European partners. Practical and unforeseeable problems are addressed that occurred during the project implementation and ways how they were successfully solved are reported. The major problems in many African institutions were administrations that are not used to work in multi-national consortia and a lack of institutional support for the African researchers. In Europe a misjudgement of the African boundary conditions as well as inflexible administrations caused problems. Finally the funding scheme did not always allow to easily overcome the high number of unexpected practical problems. A major deficit identified during the project was a general trend in Africa to underestimate the role of research for the development of the continent. Most universities focus on teaching applied sciences, which is without doubt important to cover the market need for qualified staff in the rapidly growing African industries. However, this makes it unattractive for highly qualified performers to conduct research on the continent. Furthermore this leads to the situation that the curricula can only contain second hand knowledge. In order to attract international high level researchers, it is suggested to install multi-national regional excellence research centres that only promote PhD and post-doc research on a level that can cope with highest international excellence. High level research is often perceived as not capable of focusing on immediate actual problems that many African economies have to cope with.. However, it is considered to be very sustainable in terms of autonomy and mastering future challenges. T2 - ACCTA - International conference on advances in cement and concrete technology in Africa 2013 CY - Johannesburg, South Africa DA - 28.01.2013 PY - 2013 SN - 978-3-9815360-3-4 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. SP - 1177 EP - 1184 AN - OPUS4-27762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Vasilic, Ksenija A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Meng, Birgit ED - Stark, J. T1 - Experimental and numerical studies on calibration of a rotational rheometer for cementitious materials T2 - 17. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 2009-09-23 PY - 2009 SN - 978-3-00-027265-3 VL - 1 SP - 1-1135 - 1-1140 CY - Weimar AN - OPUS4-20300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vasilic, Ksenija A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Haamkens, Frank A1 - Mechtcherine, V. A1 - Roussel, N. T1 - Flow of fresh concrete through reinforced elements: Experimental validation of the porous analogy numerical method N2 - Numerical simulations of concrete castings are complex and time consuming. In order to decrease simulation time and to simplify simulation procedure, an innovative modelling approach, which treats reinforced sections in a formwork as porous media, was proposed. In the previous studies, this numerical model was proved suitable to simulate casting of model yield-stress fluids through reinforced elements. This article focuses on the experimental validation of the proposed model at the concrete scale. For this purpose, a large-scale laboratory casting of a highly reinforced beam is performed. The casting process is numerically simulated and the numerical results are compared to the experimental measurements. KW - Porous medium KW - Self-compacting concrete KW - Casting KW - CFD simulation KW - Reinforcement PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S0008884616301880 DO - https://doi.org/10.1016/j.cemconres.2016.06.003 SN - 0008-8846 VL - 2016/88 SP - 1 EP - 6 PB - Elsevier Ltd. AN - OPUS4-37441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten T1 - Improvement of durability of SCC by the use of micro fly ash and limestone filler T2 - BAM-Präsentation Nanocem-Meeting CY - Copenhagen, Denmark DA - 2006-04-25 PY - 2006 AN - OPUS4-12475 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Meng, Birgit A1 - Brouwers, H.J.H. ED - Aguiar, J. B. ED - Jalali, S. ED - Camoes, A. ED - Ferreira, R.M. T1 - Influence of ambient temperature conditions on the effect of stabilising polymers in cementitious building materials T2 - 13th International Congress on polymers in concrete - ICPIC 2010 CY - Funchal-Madeira, Portugal DA - 2010-02-11 KW - Stabilising agent KW - Polycarboxylate ether KW - Polysaccharides KW - Starch ether KW - Biopolymers KW - Rheology KW - Setting PY - 2010 SN - 978-972-99179-4-3 SP - 241 EP - 248 CY - Funchal-Madeira, Portugal AN - OPUS4-21971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten A1 - Meng, Birgit T1 - Influence of environmental temperatures on the performance of polymeric stabilising agent in fresh cementitious materials N2 - Stabilising admixtures are commonly used additives in repair mortars and grouts. Beyond this, such type of admixture is increasingly used in concrete and other cementitious materials. In particular when fresh mortar or concrete properties have to be adjusted reliably, stabilising agents can be beneficially used to improve workability and robustness of the mixture. The mode of operation of these admixtures varies, rather affecting either the liquid phase or the solid particles in the dispersion, both causing strong interactions with the mortar or concrete system, and significant changes in their rheological behaviour. Furthermore, these are strongly affected by the environmental temperature during the casting process. In the paper the effect of temperature on the performance of stabilising agents in cementitious systems is presented and how performance changes affect fresh and hardening mortar or concrete properties. Particular attention is placed on interactions between stabilising agents and superplasticizers. Results are discussed with special focus on self-compacting concrete. KW - Biopolymers KW - Cementitious materials KW - Polycarboxylate ether KW - Rheology KW - Setting KW - Stabilising agent KW - Starch ether KW - Self-compacting concrete KW - Superplasticizer PY - 2011 DO - https://doi.org/10.4028/www.scientific.net/KEM.466.97 SN - 1013-9826 VL - 466 SP - 97 EP - 104 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-22853 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Carvello, J. M. F. A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Fiorotti Peixoto, R. A. T1 - Influence of high-charge and low-charge PCE-based superplasticizers on Portland cement pastes containing particle-size designed recycled mineral admixtures N2 - Design : and use of engineered recycled mineral admixtures obtained from industrial and mineral waste are promising strategies to increase the range of materials suitable for use in cement-based composites. In this work, Portland cement-blended pastes containing mineral admixtures designed for improving particle packing were evaluated in the presence of low- and high-charge polycarboxylate-based superplasticizers. The powders were obtained from basic oxygen furnace slag, iron ore tailings, quartz mining tailings, and quartzite mining tailings. The zeta-potentials of the particles were obtained via electrophoretic mobility. The flow properties were evaluated by rheological tests performed in a Couette type rheometer. The hydration kinetics was evaluated by isothermal calorimetry and an adapted method based on the Vicat needle test. The high-charge PCE and the finer mineral admixtures produced more stable blends. Coarser mineral admixtures led to increased flowability and delayed hydration compared to finer ones. Steel slag powders presented the most significant plasticizer effects, but also the largest setting delays and segregation tendency. Quartz-rich superfines reduced the setting delays caused by the superplasticizers. In summary, both superplasticizers were effective in improving flow properties, but the high-charge PCE was effective in preventing segregation in pastes containing mineral admixtures coarser and heavier than cement. KW - Engineered recycled mineral admixtures KW - Rheology KW - PCE-Based superplasticizer KW - Steel slag KW - Mining tailing PY - 2020 DO - https://doi.org/10.1016/j.jobe.2020.101515 VL - 32 SP - 1 EP - 16 PB - Elsevier AN - OPUS4-58395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Franco de Carvalho, J. M. A1 - Defàveri, K- A1 - Castro Mendes, J. A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Fiorotti Peixoto, R. A. T1 - Influence of particle size-designed recycled mineral admixtures on the properties of cement-based composites N2 - In this work, engineered recycled mineral admixtures were obtained from four different industrial residues: basic oxygen furnace slag, iron ore tailings, quartz mining tailings and quartzite mining tailings. The grinding performance was evaluated in two different programs and the characterization included chemical and mineralogical composition, particle morphology, and physical properties. Performance evaluations were carried out in blended pastes and mortars, including flow properties, hydration kinetics, soundness, pozzolanic activity, and compressive strength. Coarser-than-cement admixtures allowed better flow performance, greater dimensional stability and more economical production, while finer-thancementn admixtures improved mechanical performance by both filler effect and cementing activity. KW - Engineered recycled mineral admixtures KW - Rheology KW - Hydration kinetics KW - Basic oxygen furnace slag KW - Iron ore tailings KW - Mining tailings PY - 2021 DO - https://doi.org/10.1016/j.conbuildmat.2020.121640 SN - 0950-0618 VL - 272 SP - 1 EP - 13 PB - Elsevier Ltd. AN - OPUS4-58255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leinitz, Sarah A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten ED - Priebe, Nsesheye Susan T1 - Influence of stabilising agents on limestone filler and cement pastes N2 - The paper showed that the STA behave completely different in pastes with LSF and cement, respectively, as well as with or without PCE. While STA can affect plastic viscosity and yield stress in LSF and cement pastes, the addition of PCE causes that the STA have mainly an impact on plastic viscosity, except DGUM and ST-low. The performance of STA in LSF and cementitious systems can vary greatly due to different ionic strengths of the liquid phase. The charges due to modification of the starches have an intense influence on the rheological properties in pastes. The combined use of PCE and STA can lead to a significant increase of the plastic viscosity without a strong effect to the yield stress. For the evaluation of the effectivity of STA the ionic strength of the liquid phase and the solid volume fraction of the binder have to be taken into account. Further influences can arise from grain size and aggregate content as well as the temperature, which were not discussed in this paper. T2 - 3rd Symposium on Knowledge Exchange for Young Scientists (KEYS) CY - Johannesburg, South Africa DA - 26.06.2017 KW - Stabilising agent KW - Limestone filler KW - Cement PY - 2017 SN - 978-3-9818270-7-1 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. VL - 3 SP - 143 EP - 146 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-41000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten A1 - Meng, Birgit T1 - Influences of superplasticizer modification and mixture composition on the performance of self-compacting concrete at varied ambient temperatures N2 - The fresh behaviour of self-compacting concrete (SCC) at varying temperatures differs from that of normal vibrated concrete. This is because the rheology of SCC depends not only on degree of cement hydration, but also on the adsorption of superplasticizers – mostly polycarboxylate based polymers (PCE) -, which is affected by the time and hydration progress. Due to the variety of PCEs and mixture compositions for SCC a prediction of the rheology at varying temperatures is complicated. The charge densities of PCEs as well as the water to solid ratio in the paste are identified to be the main decisive parameters for robust fresh concrete properties. Rheometric concrete investigations with different SCC mixture compositions and varied anionic charge densities of the PCE were conducted. SCC which is rich in powder components showed robust performance at low temperatures while SCC with low powder content was favourable at high temperatures. High charge density PCE pointed out to be very robust at low temperatures but at high temperatures it significantly reduced the flow retention. Low charge density PCE could not generate self-compacting properties at low temperatures but retained the flow performance over sufficiently long time. Based on considerations about particle interactions and adsorption mechanisms of PCEs, the relevant processes are explained and options for the development of robust mixture compositions for individual temperature ranges are itemised. KW - Polycarboxylate ether KW - Temperature KW - Rheology KW - Mixture composition KW - Self-compacting concrete PY - 2014 DO - https://doi.org/10.1016/j.cemconcomp.2013.12.004 SN - 0958-9465 SN - 1873-393X VL - 49 SP - 111 EP - 126 PB - Elsevier CY - Barking, Essex AN - OPUS4-30552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten A1 - Meng, Birgit T1 - Interactions between PCE and different polysaccharides and influences on the early hydration of cement N2 - ln order to observe the influence of stabilising agents (STA) based on starch and diutan gum, rheometric experiments and setting tests were conducted on cement pastes with and without PCE superpiasticizers. The results show that with regard to yield stress both STAs show differing behaviours in Systems without PCE. In presence of PCE, yield stress infiuences of the STAs retreat into the background. The Vicat results exhibit that STAs can reduce the retard ing effect of PCE. T2 - 1st International conference on the chemistry of construction materials CY - Berlin, Germany DA - 07.10.2013 PY - 2013 SN - 978-3-936028-75-1 N1 - Serientitel: GDCh-Monographien – Series title: GDCh-Monographien VL - 46 SP - 49 EP - 52 AN - OPUS4-30045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barthel, Maria A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Rübner, Katrin ED - Schmidt, Wolfram ED - Priebe, Nsesheye Susan T1 - Interactions between waste paper sludge ashes and superplasticizers based on polycarboxylates N2 - In many industrial nations, about two third of the paper demand is covered by recovered paper. A major process step within the treatment of waste paper is the de-inking. It is a floating process yielding paper sludge as a waste product. About 50 % of this residue is used as a fuel. In several cases it is burnt at temperature of about 850 °C and thereafter the accrued ashes are collected in the flue gas filter. During the combustion, kaolinite and calcium oxide generate gehlenite and larnite. Calcite is the main component of waste paper sludge ash (PA).The chemical and mineralogical composition of PA suggests using it as a supplementary cementitious material. In modern construction materials technology, workability aspects gain importance, since for most modern materials the rheology and compaction ability are relevant for the operation at a hardened state. It was observed that PA significantly increases the water demand of powder systems, which can cause serious problems during the casting of mineral binder systems containing PA. It is therefore obvious that binder systems containing PA might demand for the use of superplasticizers. Superplasticizers are polymers with anionic backbone that cause electrostatic and steric repulsion effects upon adsorption on surfaces of particles and hydration phases. In this paper interactions between superplasticizers and waste paper sludge ashes are discussed and analysed. Based on observations of changes in the zeta potential and the dispersion of the particle system, the influence of the charge density of superplasticizers is observed and time dependent effects are demonstrated. T2 - 2nd International Conference on Advances in Cement and Concrete Technology in Africa CY - Dar es Salaam, Tanzania DA - 27.01.2016 KW - Waste paper sludge KW - Rheology KW - Cement KW - Concrete KW - Polycarboxylate ether PY - 2016 SN - 978-3-9817502-3-2 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. SP - 181 EP - 186 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-36877 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten A1 - Meng, Birgit T1 - Interactions of polysaccharide stabilising agents with early cement hydration without and in the presence of superplasticizers N2 - Polysaccharides are incorporated into cement based Systems in order to modify the rheological properties. Typically, cellulose ethers, sphingan gums, guar gum or starch ethers are applied. Depending upon their chemistry, molecular architecture, and adsorption tendency, polysaccharides interact differently with the entire cementitious system. Some stabilising agents like diutan gum mainly affect the cementitious paste; other stabilising agents like starch tend to interact with the sand fraction and even with the coarse aggregates. Cellulose and guar gum shows more diverse performances. Typically stabilising admixtures like polysaccharides are used, when sophisticated rheological properties are adjusted. Therefore, polysaccharides are often used in combination with superplasticisers, which are added to reduce the yield stress of concrete. This can cause interactions, particularly when the stabilising Agent shows a strong tendency to adsorb on particle surfaces. Adsorptive stabilising agents may reduce the amount of adsorbed superplasticisers, thus affecting both viscosity and yield stress, while non-adsorptive stabilising agents mainly affect the plastic viscosity independently of the superplasticiser. Due to the strong influence of superplasticisers on the yield stress, influences of the stabilising agent on the yield stress retreat into the background, so that their major effect is an increase of the plastic viscosity. The paper provides a comprehensive overview of how different polysaccharide superplasticisers affect cementitious flowable systems and points out the challenges of the combined use of polysaccharides and superplasticisers. Based on rheometric experiments and observations of the hydration process, time dependent effects on the workability as well as of the hydration of cement are presented and discussed. KW - Concrete KW - Polysaccharides KW - Rheology KW - Stabilising agents KW - Starch KW - Sphingan PY - 2017 DO - https://doi.org/10.1016/j.conbuildmat.2016.11.022 SN - 0950-0618 SN - 1879-0526 VL - 139 SP - 584 EP - 593 PB - Elsevier AN - OPUS4-40597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten T1 - Kusum-Kontrollkarten mit V-Maske in der Prozesssteuerung N2 - Seit Juli 2014 liegt die EN 206:2014 als neue Betonnorm vor. Neben kleineren Änderungen ergibt sich hierdurch als einschneidende Änderung zur Vorgängerversion EN 206-1:2008 ein ergänzendes Konzept zur Konformitätsbewertung der Druckfestigkeit von Beton. An dieser Stelle werden neben dem bekannten Mittelwertkriterium alternativ sogenannte Kontrollkartenverfahren möglich. Für die Konformitätsbewertung stellt in diesem Zusammenhang insbesondere die Kusum-Methode (kumulierte Summen, aus dem Englischen cusum – cumulative sum) ein Novum dar. Weiterführende Informationen zu Kusum-Methode in der Konformitätsbewertung können der Literatur entnommen werden. Eigentlich ist die Kusum-Methode aber nicht für die Konformitätsbewertung entwickelt worden, sondern vielmehr für die Produktionskontrolle. Der Unterschied zwischen Konformitätsbewertung und Produktionskontrolle ergibt sich daraus, dass die Konformitätskontrolle eine Bedeutung für die öffentliche Sicherheit hat und dass eindeutige technische Grenzwerte vorliegen müssen, die nicht unterschritten werden dürfen, während die Produktionssteuerung ein Werkzeug mit frei wählbaren Grenzwerten für Hersteller ist. Der Handlungsbedarf ist für die Produktionskontrolle optional und ergibt sich in der Regel aus Wirtschaftlichkeitsbetrachtungen. PY - 2015 SN - 1439-7706 IS - 4 SP - 38 EP - 44 PB - ad-media-Verl. CY - Köln AN - OPUS4-33580 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shamsuddoha, Md A1 - Hüsken, Götz A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Baeßler, Matthias T1 - Long-term mechanical and shrinkage properties of cementitious grouts for structural repair N2 - Grouts have numerous applications in construction industry such as joint sealing, structural repair, and connections in precast elements. They are particularly favoured in rehabilitation of structures due to penetrability and convenience of application. Grouts for repair applications typically require high-performance properties such as rapid strength development and superior shrinkage characteristics. Sometimes industrial by-products referred as supplementary cementitious materials (SCM) are used with neat cement due to their capabilities to provide binding properties at delayed stage. Micro silica, fly ash and metakaolin are such SCMs, those can modify and improve properties of cement products. This study aims at investigating long-term mass loss and linear shrinkage along with long-term compressive and flexural strength for grouts produced from ultrafine cement and SCMs. A series of mixtures were formulated to observe the effect of SCMs on these grout properties. Properties were determined after 365 days of curing at 23oC and 55% relative humidity. The effect of SCMs on the properties are characterised by statistical models. Response surfaces were constructed to quantify these properties in relation to SCMs replacement. The results suggested that shrinkage was reduced by metakaolin, while micro silica and fly ash had positive effects on compressive and flexural strength, respectively. T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) CY - Rovinj, Croatia DA - 20.03.2019 KW - Grout KW - Long-term shrinkage KW - Micro silica KW - Fly ash KW - Metakaolin PY - 2019 DO - https://doi.org/10.21809/rilemtechlett.2019.82 SN - 2518-0231 VL - 4 SP - 9 EP - 15 PB - RILEM Publications SARL CY - 4 avenue du Recteur Poincaré, 75016 Paris, France AN - OPUS4-48712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Barthel, Maria A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten T1 - Mitigation of the urban heat island effect by self-cooling concrete pavers N2 - Worldwide an increasing migration from rural to urban regions can be observed. Hence cities are growing and as a result the building density and the land sealing rise. Concrete as commonly used building material in urban structures provides a high heat storage capacity. Therefore the microclimate in cities has become warmer than in the surrounding areas. This phenomenon is called Urban Heat Island Effect. To mitigate this situation a large scale application of self-cooling concrete pavers is an approach to reduce the urban heat island effect. Making use of evaporation enthalpy, this new type of pavements counterbalances the absorption of solar radiation and the subsequent transfer of heat to the surrounding environment. The typical double-layer structure of concrete paving stones can be maintained. The mass concrete acts as a water storage layer and is covered by a permeable face concrete. As the different requirements of these layers demand different concrete mixtures, they are developed and optimised for their respective functions. This paper presents some suitable no-slump concrete mixtures that combine a sufficient compressive strength as well as good water transportation properties for the above mentioned approach. KW - Pavement KW - Urban heat island KW - No slump concrete KW - Fibers PY - 2013 SN - 2225-0514 SN - 2224-5790 VL - 4 SP - 35 EP - 39 PB - International Institute for Conservation of Historic and Artistic Works CY - New York, NY, USA AN - OPUS4-29931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vasilic, Ksenija A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Roussel, N. T1 - Model of SCC flow through reinforced sections: experimental validation N2 - This study focuses on concrete flow in presence of obstacles and develops a mathematical model and a computational approach for SCC flow through reinforced formworks. In order to decrease high computational times needed to simulate castings through reinforced elements, an innovative approach to model the reinforced sections as porous media is proposed here. In the previous work, this numerical model is proved able to simulate the free-surface flow of non-Newtonian fluids through the reinforcement networks. In the present study, the applicability of the model on the concrete flow will finally be proved. The large-scale form-filling experiments with SCC will be conducted and the experiments will be simulated using the proposed numerical model. The numerical model will then be validated through the comparison of the experimental results and the results of the numerical simulations. T2 - 7th RILEM International Conference on Self-Compacting Concrete and 1st RILEM International Conference on Rheology and Processing of Construction Materials CY - Paris, France DA - 02.09.2013 KW - Porous medium KW - Rheology KW - Numerical modelling KW - Reinforcement PY - 2013 SN - 978-2-35158-137-7 SN - 978-2-35158-138-4 SP - 229 EP - 236 PB - RILEM Publishing S.A.R.L CY - Paris, France AN - OPUS4-37442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barthel, Maria A1 - Kühne, Hans-Carsten A1 - Schmidt, Wolfram ED - Bager, D. H. ED - Silfwerbrand, J. T1 - Multilayer concrete pavers - solutions for the mitigation of the urban heat island effect N2 - The large scale application of self-cooling concrete pavers is a future-oriented approach to reduce the urban heat island effect in inner-city areas. Making use of evaporation enthalpy, these new pavements counterbalance the absorption of solar radiation and the subsequent transfer of heat to the surrounding environment. The concrete pavers consist of a permeable top-layer and a storage layer. As the different requirements of these layers demand different concrete mixtures they are developed and optimised for their respective functions. This paper presents some results of the concrete mixture design and Solutions that combine a sufficient compressive strength as well as good water transportation properties for the face concrete layer. T2 - fib Symposium Stockholm 2012 'Concrete structures for a sustainable community' CY - Stockholm, Sweden DA - 11.06.2012 KW - Urban heat island effect KW - Concrete multilayer pavers KW - Permeability KW - Fibre concrete PY - 2012 SN - 978-91-980098-1-1 SP - 513 EP - 516 PB - Royal Institute of Technology CY - Stockholm AN - OPUS4-27271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vasilic, Ksenija A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Roussel, N. T1 - Numerical modelling of SCC flow through reinforced sections T1 - Numerische Simulation des Fließverhaltens von SVB durch bewehrte Querschnitte N2 - The study introduces the porous medium model for the simulation of concrete flow through highly-reinforced sections. It shows that numerical simulations can predict concrete behavior during casting and help to avoid expensive mistakes. N2 - Bei der hier dargestellten Untersuchung wird das Modell des porösen Mediums auf die Simulation des Fließverhaltens von Beton durch Querschnitte mit hohem Bewehrungsgrad angewandt. Dabei zeigt sich, dass mit Hilfe numerischer Simulationen das Verhalten des Betons während der Betonage prognostiziert und kostspielige Fehler vermieden werden können. PY - 2015 SN - 0373-4331 SN - 1865-6528 N1 - Sprachen: Deutsch/Englisch - Languages: German/English VL - 81 IS - 03 SP - 50 EP - 55 PB - Bauverl. CY - Gütersloh AN - OPUS4-33151 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -