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Menefy, Luke. "Investigation of Reactive Powder Concrete and it's Damping Characteristics when Utilised in Beam Elements". Thesis, Griffith University, 2008. http://hdl.handle.net/10072/365692.
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Reactive Powder Concrete (RPC) is a relatively new ultra high strength concrete with a
wide range of capabilities. Currently it is used in high performance applications where
either impact resistance, high durability and/or member size are governing factors in
design. The relatively high cost, required production control, and lack of industry
knowledge have generally precluded its widespread use in more common engineering
applications. Accordingly, the major component of this Thesis aims to contribute new
knowledge with respect to the understanding of the material behaviour and damping
characteristics of RPC. To achieve this goal a staged experimental study was
undertaken encompassing the following (1) the production and material behaviour
including a parallel study on the durability of RPC in an aggressive environment (2) the
static performance and damping characteristics of RPC when utilised in beam elements.
The initial component of the investigation involved several trial mix programmes to
ascertain the viability of RPC production using local Queensland materials. A further
large scale production programme of RPC was carried out utilising two mixer types:
(1) vertical pan mixer representing a precast mix and (2) a mobile inclined drum mixer
representing an onsite mix. The results indicated that the onsite application of RPC was
viable and resulted in only a minor reduction in characteristic strengths when
compared to precast operations. A parallel experimental study investigating the relative
performance of RPC immersed in acidic solutions indicated that the range of RPC’s
investigated were more susceptible to sulphuric acid attack when compared to a
standard high strength concrete (HSC) used in the investigation.
Following verification of RPC characteristic strengths, twenty three test beams were
produced as part of a large scale RPC production programme. These test beams were
incrementally loaded to failure under simply supported conditions during which static
measurements were observed both under load and upon the removal of load. The results
indicated that the fibre reinforced (FR) RPC test beams exhibited a higher load
capacity, an increase in first cracking loads, significantly reduced crack widths and an
overall reduction in shear behaviour when compared to the non-fibre reinforced (NF)
RPC and HSC test beams.
Concurrent free vibration tests through the use of an impulse force hammer were
carried out during the static loading of each of the twenty three test beams in an effort
to ascertain the damping characteristics throughout the various levels of test beam
damage. A new program using analytical and theoretical techniques was developed to
analyse the excitation response histories (ERH) obtained at each load increment, the
program was found to be more efficient when compared to previous analysis methods. A
method of assessing the current and previous analysis methods was also incorporated
within the program enabling the user to compare the damping ratio determined through
the various analysis methods.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
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Helmi, Masdar. "Thermo-physical properties and high-temperature durability of reactive powder concrete (RPC)". Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/33991/.
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The popular use of concrete, particularly in the construction industry, has continually challenged researchers to advance its performance to new levels. Research in this area has led to substantial ideas of reactive powder concrete (RPC) which is developed by controlling three main variables: composition, pressure during setting period, and post-set heat curing. A growing community of research has emerged to define the physical and mechanical properties of RPC, but to date few have focussed on the high temperature behaviour and aging effects after exposure to fireand that influence the durability of concrete. This research aimed to characterise the thermo-physical properties of RPC and to quantify the microstructural transformation caused by (i) high temperature curing, and (ii) fixed and cyclic high temperature exposure (at 28-day strength). The experimental work mainly used a RPC mixture and involved three defined stages. Firstly, the optimisation of RPC was investigated by analysing the mix composition and measuring the corresponding mechanical properties of RPC with variables such as heating rate, heating duration, and starting time of heating. Secondly, the transformation of microstructural properties was investigated with respect to the pre- and post-treatment conditions and included pore network evolution, elemental composition, and image analysis of the interfacial transition zone (ITZ). Thirdly, the response to high temperature exposure was analysed by focussing on the residual compressive strength and alteration of microstructural properties (after both static and cyclic temperature exposure of varying levels). The main findings are summarised as follows: (1) heat curing appears to have optimum impact (after casting) at a ramp rate of 50 °C/hr for 48 hours; (2) heat curing treatment induced some effects such as pore filling by tobermorite and xonotlite, with some dehydroxilation of C-S-H gel and Ca (OH)2; (3) the thermo-physical properties of RPC were all reduced following heat treatment/ exposure due to crack network progression; (4) after elevated temperature exposure, the compressive strength of RPC decreases due to differential shrinkage between the matrix and aggregate phases.
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Warnock, Robyn Ellen Civil & Environmental UNSW. "Short-term and time-dependent flexural behaviour of steel fibre-reinforced reactive powder concrete". Awarded by:University of New South Wales. Civil and Environmental, 2006. http://handle.unsw.edu.au/1959.4/23027.
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This thesis presents an experimental and theoretical study of the material and structural behaviour of a Steel-Fibre reinforced Reactive Powder Concrete (SF-RPC). The experimental program consisted of three phases. Phase 1 involved the development of a design mix for use throughout the remainder of the study. Phase 2 consisted of an in-depth investigation into the material properties of the mix. The final phase of the experimental component was the testing of 16 plain and prestressed SF-RPC beams. Twelve beams were tested under short-term loading to determine their cracking and ultimate moment capacity. The remaining 4 beams were used to investigate the time-dependent flexural behaviour of prestressed SF-RPC slabs. The material properties were measured using a range of short-term tests and included the compressive and flexural behaviour, static chord modulus of elasticity and crack mouth opening. In addition to the short-term tests, investigation into the time-dependent material behaviour was undertaken and included the creep and shrinkage characteristics of the material. The response of the material to various curing conditions was also investigated. The structural behaviour investigated included the short-term flexural moment-curvature response and load-deflection behaviour of beams and slabs along with the crack patterns of both plain and prestressed SF-RPC members. In addition to the investigations into the short-term flexural behaviour, a study into the time-dependent flexural behaviour was also undertaken. There are currently 2 available models for predicting the flexural response of plain and prestressed RPC cross-sections. The analytical phase of this investigation involved an evaluation of these models. Based on the experimental findings and analysis, a modified model was proposed for calculating the short-term flexural behaviour of plain and prestressed SF-RPC beams. The applicability of an age-adjusted effective modulus method for calculating the time-dependent deformations of prestressed SF-RPC slabs under various levels of sustained loads was also evaluated and found to be adequate with minor refinements.
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Gao, Xiang y S3090502@student rmit edu au. "Mix Design and Impact Response of Fibre Reinforced and Plain Reactive Powder Concrete". RMIT University. Civil, Environmental and Chemical Engineering, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080424.150722.
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Concrete is the most broadly used material in construction worldwide and Reactive Powder Concrete (RPC, a type of ultra high performance concrete) is a relatively new member of the concrete family. In this work the critical parameters of RPC mix design are investigated and the mix design is explored through a program of concrete casting and testing. Owing to the enhanced microstructure of RPC, porosity and permeability can be significantly decreased in the concrete matrix. This benefits the durability characteristics of RPC elements resulting in a longer service life with less maintenance costs than conventional concrete. It has been used for high integrity radiation waste material containers because of its low permeability and durability. Fibre reinforced RPC is also ideal for use in long span and thin shell structural elements without traditional reinforcement because of its advantageous flexural strength. Moreover, due to improved impact resistance, RPC can be widely employed in piers of bridges, military construction and blast protection. There is no standard approach to assessing the impact resistance of concrete. This investigation utilises relatively well accepted impact equipment to evaluate the mechanical properties of RPC under dynamic loading. The compressive and flexural tensile strengths of plain and fibre reinforced RPC are investigated using a variety of specimens and apparatus. The dynamic increase factor (DIF) is evaluated to indicate the strain rate sensitivity of the compressive and flexural strength.
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Vanderlei, Romel Dias. "Análise experimental do concreto de pós reativos: dosagem e propriedades mecânicas". Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-23082006-095043/.
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A tecnologia dos materiais a base de cimento Portland vem se desenvolvendo rapidamente, onde a melhoria das propriedades mecânicas vem sendo alcançada, eliminando os agregados graúdos e estudando a composição granulométrica da mistura, procurando preencher os vazios utilizando materiais finos e ultrafinos, como pó de quartzo e a sílica ativa. Esta pesquisa tem como objetivos: desenvolver concreto de pós reativos com resistência à compressão próxima de 200 MPa e módulo de elasticidade acima de 45 GPa; propor uma relação constitutiva para o material, considerando o volume de fibras; especificar as deformações máximas na tração e na compressão; e verificar a influência das fibras nas resistências à compressão e à tração na flexão. Para isso, foi utilizado o método de empacotamento das partículas sólidas, com o intuito de definir composições granulométricas, e desenvolveu-se técnicas necessárias para a moldagem, adensamento e cura térmica. A análise experimental compreendeu o estudo das seguintes propriedades: resistência à compressão, módulo de elasticidade, resistência à tração na flexão, deformações e ductilidade. As fibras metálicas melhoraram as propriedades mecânicas e aumentaram a ductilidade do concreto. A temperatura de cura e o tempo de submissão ao tratamento térmico, tornou o material mais resistente. A deformação específica máxima na compressão foi definida experimentalmente como 4,3%. O limite elástico para as deformações de tração ficou em 0,28%. Foi proposta uma relação constitutiva para tensões de compressão, que pode ser utilizada para concretos de pós reativos, com resistência à compressão próxima de 200 MPa e taxa de fibras até 4% em volume. Os resultados obtidos indicam que o concreto de pós reativos desenvolvido apresentou altas resistências à compressão e à tração na flexão, onde a microestrutura do material mostrou-se com baixíssima porosidade e interface pasta - agregado praticamente suprimida. A tecnologia desenvolvida nesta pesquisa pode ser considerada um grande avanço na tecnologia de materiais a base de cimento Portland que, com maiores aperfeiçoamentos, espera-se a aplicação desse material em situações que tirem proveito das excelentes propriedades mecânicas e durabilidadeThe technology of Portland cement materials has developed quickly, where the improvement of the mechanical properties has been reached, eliminating the coarse aggregates and studying the granular mixture, in order to fill the emptiness with fine and ultra-fine materials, like crushed quartz and silica fume. The present paper aimed: develop reactive powder concrete with compressive strength close to 200 MPa and module of elasticity above 45 GPa; propose a strength x strain relationship in compression for the material considering the volume of fibers; specify the maximum strain in the traction and in the compression; and to verify the influence of the fibers in the compression strength and in the bending strength. It went using the method of packing of the solid particles to define the grain size distribution, and necessary techniques were developed for the preparation and thermal cure. The experimental analysis understood the study of the following properties: compression strength, module of elasticity, bending strength, strain and ductility. The metallic fibers improved the mechanical properties and they increased the ductility of the concrete. The cure temperature and the time of submission to the thermal treatment, improved the compression strength. The maximum strain in the compression was defined experimentally as 4,3%. The elastic limit for the traction strain was 0,28%. A strength x strain relationship in compression was proposed, and can be used in reactive powders concrete, with compression strength of around 200 MPa and rate of fibers of up to 4% of volume. The results indicate that the reactive powders concrete developed presented excellent compression strength and bending strength, and the material presented a microestrutura with low porosity. The technology developed in this research can be considered a great progress in the technology of materials with Portland cement, and the application of that material is expected in situations that use advantage of the excellent mechanical properties and durability
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Christ, Roberto. "Desenvolvimento de compósitos cimentícios avançados à base de pós-reativos com misturas híbridas de fibras e reduzido impacto ambiental". Universidade do Vale do Rio dos Sinos, 2014. http://www.repositorio.jesuita.org.br/handle/UNISINOS/3207.
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itt Performance - Instituto Tecnológico em Desempenho da Construção Civil
O desenvolvimento de novos concretos vem sendo ampliado ao longo dos anos, o que ocorre paralelamente ao aprimoramento dos cálculos estruturais e ao maior conhecimento sobre as propriedades dos materiais, o que conduz os projetistas ao desenvolvimento de estruturas que necessitam ter características específicas. Com isso surge a necessidade de se desenvolver concretos especiais, que apresentam elevada resistência mecânica e durabilidade. O concreto de pós reativos, também chamado de CPR, é um exemplo destes materiais. Trata-se de um concreto de ultra alto desempenho, com elevada resistência mecânica, extremamente dúctil e de baixa porosidade. Este tipo de concreto apresenta propriedades mecânicas superiores em comparação aos concretos de alta resistência, chegando a resistências à compressão de 200 MPa, à tração de 45MPa e módulo de elasticidade superior a 50 GPa. O consumo de cimento neste tipo de concreto pode atingir 800 kg/m3, além de incorporar elevado volume de sílica ativa. A otimização granular dos constituintes, realizada através de métodos de empacotamento de partículas, faz com que seja possível obter um material com o mínimo de vazios e elevada densidade. As fibras introduzidas no composto proporcionam elevada ductilidade. Neste trabalho, parte do cimento Portland foi substituído por cinza volante, para desenvolver um CPR com baixo consumo de aglomerantes. Também foi estudada a incorporação de dois tipos de fibras, ou hibridização, para uma matriz de CPR com menor consumo de cimento. A introdução de dois tipos distintos de fibras proporciona ao material maior sinergia, diminuindo a formação e a propagação de fissuras durante o carregamento. Os resultados obtidos nesta pesquisa mostram que a substituição parcial do cimento por cinza volante apresentou melhor desempenho mecânico, atingindo resistência à compressão de aproximadamente 190 MPa com 30% de adição. A incorporação de dois tipos distintos de fibras, aço e polipropileno em teores de 80% e 20% respectivamente, proporcionou ao material elevada resistência à tração na flexão e tenacidade. Portanto, é possível dosar CPR com menores consumos de cimento e uso de dois tipos de fibras, melhorando as propriedades da mistura e obtendo um compósito com reduzido impacto ambiental.
The development of new concretes is being expanded over the years, withal the improvements in structural design, along the increased knowledge of materials properties, which leads the designers to develop structures with specific requirements. It arises the need of the development of special concretes, with have enhanced mechanical strength and durability. Reactive powder concrete, also called RPC, is an example of these materials. This is an ultra-high-performance concrete with high mechanical strength, extremely ductile and low porosity. This type of concrete has superior mechanical properties compared to high strength concrete, reaching compressive strengths of 200 MPa, tensile strengths of 45 MPa and modulus higher than 50 GPa. The cement consumption in this type of concrete may reach 800 kg/m3, while incorporating high volumes of silica fume. The optimization of granular constituents accomplished by particle packing methods provides a material with a minimum of voids and also high density. The fiber introduced into the material compound provides high ductility. On this report, fly ash was used to replace some part of the cement, aiming the development of a RPC with low agglomerate consumption. It was also studied the use of two types of fiber, or hybridization, to a RPC matrix array of CPR with less consumption of cement. The introduction of two distinct types of fibers gives the material improved synergy, decreasing the formation and propagation of cracks during the charging. The results obtained in this study show that the partial replacement of cement by fly ash gives better mechanical performance, reaching the compressive strength of approximately 190 MPa with 30% addition. The incorporation of two different types of fibers, steel and polypropylene at levels of 80% and 20% respectively, provided the materials high tensile strength and toughness. Therefore, it is possible to compose an RPC with lower cement consumption and use of two types of fibers, improving the properties of the mixture and obtaining a composite with reduced environmental impact.
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Cherkaoui, Khalid. "Caractérisation de la microstructure et comportement à court et long terme d'un Béton de Poudre Réactive extrudable". Thesis, Evry-Val d'Essonne, 2010. http://www.theses.fr/2010EVRY0046/document.
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Les Bétons de Poudre Réactive (BPR) sont connus pour leur résistance très élevée et leur bonne durabilité, mais aussi pour leur prix élevé. L’objectif de cette étude concerne la mise au point d’une formulation de BPR extrudable (BPR). Des essais préliminaires d’écoulement au mini cône d’Abrams ont été réalisés avec des teneurs variées en superplastifiant et en substituant partiellement la fumée de silice par du quartz broyé. Cinq mélanges ont été retenus et caractérisés de façon systématique au microscope électronique à balayage et en diffraction des Rayons X. Une étude complète de retrait au jeune âge, de résistance mécanique et de durabilité face à l’azote et aux ions chlorure a été menée. Un montage expérimental d’extrusion a été mis au point. Un mélange incorporant du quartz broyé en remplacement d’une fraction de la fumée de silice et une composition optimisée en superplastifiant montre des propriétés intéressantes : extrudabilité, très bonne durabilité, performances mécaniques améliorées et retrait diminué. Sur cette composition, l’étude microstructurale met en évidence le rôle que joue le superplastifiant sur la chimie d’hydratation avec une forte consommation en bélite. Ce mélange permet ainsi de diminuer le coût de fabrication pour un BPR en permettant d’économiser la fumée de silice coûteuse et en ne nécessitant aucun traitement thermiqueReactive Powder Concrete (RPC) is well known for ultra-high mechanical performances and very good durability as well as for a high cost. The aim of this study is to find an extrudable RPC. Abrams cone preliminary tests were made with various contents of superplasticizer and a partial substitution of silica fume by crushed quartz. Then, fives concrete samples were chosen and systematically characterized by scanning electron microscopy and X-ray diffraction. Then, a complete study was made including early-age shrinkage, mechanical strength, gas permeability and chloride diffusion measurements. An experimental extruder was build. Among the five compositions, one of them, where crushed quartz replaces a part of silica fume, exhibits very good properties: good extrudability, very good durability, and better mechanical strength with an improvement of shrinkage. The microstructural study of this composition highlights the effect of the superplasticizer on hydration, with high belite consumption. This composition allows a lower cost of RPC with a decreasing of silica fume content, without thermal treatment
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Prazeres, Xavier Emídio Glórias. "Betão de elevada resistência para elementos muito esbeltos". Master's thesis, Universidade de Évora, 2011. http://hdl.handle.net/10174/11585.
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Esta dissertação pretendeu demonstrar a actual importância do desenvolvimento de betões de alta resistência na execução das mais variadas construções que vão surgindo com o avanço conjunto da tecnologia ao longo do tempo, atendendo não só a parâmetros relacionados com a resistência destes betões mas também a um dos factores que se tem vindo a tornar muito relevante na actualidade, o ambiente.
Este trabalho envolve um caso de estudo que compreendeu numa primeira fase, a concepção de um betão de elevada resistência tendo por base a utilização dos princípios da pesquisa mencionados anteriormente.
Seguidamente foram determinadas a propriedades mecânicas desse betão, sendo elas a resistência à compressão, módulo de elasticidade e fluência, em ensaios realizados ao longo de quatro meses.
Conjuntamente com estes ensaios foram fabricadas, vigas de perfil em “I” de 1,10m de comprimento, 10cm de largura, 10cm de altura, 2 cm de espessura de alma e com 2cm ou 2,4cm de espessura de banzo submetidas à rotura semanalmente e mensalmente de forma a obter a solução mais eficaz entre armadura e betão.
Concluiu-se que: É possível a concepção de um betão de elevada resistência utilizando os constituintes correntes na indústria da construção. O betão desenvolvido adequa-se à execução do tipo de vigas mencionadas ao longo do trabalho, apresentando estas, um grande potencial de desenvolvimento dado que têm elevadas resistências com pesos moderados. A metodologia de cálculo para o dimensionamento deste tipo de vigas é idêntica à utilizada no dimensionamento de peças normais; ### Abstract:
High Strength Concrete for Very Slender Elements
The main goal is to demonstrate the current importance of developing high-strength concrete. With the technology’s development, high-strength concrete has become very important in several constructions not only by the characteristics related to the concrete´s strength, but also in one of the factors that proved to be very relevant nowadays, the environment.
Initially, it was made a case study in designing a high-strength concrete based on the use of research principles outlined above. In trials conducted over four months, we determine the mechanical properties of concrete which are compressive strength, modulus of elasticity and fluency.
In order to obtain the most effective solution between armor and concrete, were fabricated beams in a "I" of 1.10 m long, 10 cm wide, 10 cm high, 2 cm web thickness with 2cm or 2.4 cm flange thickness weekly and monthly subjected to disruption.
With the goal in mind it is possible to design a high-strength concrete using the current constituents in the construction industry. The concrete is suitable for implementing this type of beams mentioned throughout the work, have enormous potential because they have high resistance with only moderate weights. The calculation methodology for the design of such beams is identical to the design of normal pieces.
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Panenková, Monika. "Reaktivní práškové kompozity a cementové kompozity bez makropórů". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372126.
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This diploma thesis deals with the design principles and manifacture of ultra performance concrete (UHPC), reactive powder composites (RPC) and other fine-grained materials, such as Macro defect free (MDF) or Densified systems with small particles (DSP). Theoretical part of this work is focused on the requirements of properties and composition UHPC and RPC and methodology of their design principles. Experimental part describes design principles RPC, manufacture of test specimens, testing of certain physical and mechanical properties, such as tensile strenght, bending strenght and compressive strenght and determination chemical character X-ray and thermal analysis.
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Sauzéat, Emmanuel. "Composition et microstructure des bétons de poudres réactives : effets des traitements thermiques et du traitement compressif". Vandoeuvre-les-Nancy, INPL, 1998. http://www.theses.fr/1998INPL113N.
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Les bétons de poudres réactives (BPR) sont des bétons à ultra-hautes performances, caractérisés par le choix rigoureux de leur composants initiaux et par des traitements post-prises. Les propriétés exceptionnelles étant dues à la qualité de leur phase liante, l'objectif de cette étude est de décrire l'évolution de cette phase, et en particulier des C-S-H, en fonction de plusieurs traitements post-prises à 20°C, 90°C, 200°C et 250°C. Dans ce but, on utilise plusieurs techniques analytiques qui permettent d'aborder la composition et l'ordre local des phases présentes, leur cristallochimie, leur minéralogie, leur agencement, l'état de la porosité à plusieurs échelle d'analyse, l'état de l'eau et les propriétés d'hydratation des C-S-H. Les résultats sont recoupés et interprétés dans le cadre d'un modèle descriptif de la phase C-S-H qui s'appuie sur ses propriétés gonflantes. Dans un premier temps on établit la spécificité des BPR par rapport aux BO et BHP en montrant en particulier qu'ils sont organisés à moyenne distance. On montre ensuite que les traitements thermiques à 90°C sont caractérisés par une organisation particulière du volume poreux et une très faible connectivité qui engendre des conditions hydrothermales légères. Dans ces conditions, on observe un épaississement statistique des feuillets des C-S-H en même temps qu'une augmentation légère de leur cristallinité. Lorsque la température de traitement augmente et atteint 200°C ou 250°C, les C-S-H subissent de façon transitoire des conditions hydrothermales poussées qui entrainent une forte augmentation de leur cristallinité, un épaississement statistique de leur feuillet et la synthèse de xonotlite dans les bulles d'air. Dans un second temps, l'eau est expulsée des BPR qui se déshydratent et se fracturent fortement, entrainant une augmentation importante de leur porosité accessible et de la taille moyenne des pores.
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Dvořáková, Tereza. "Studium hydratace RPC (Reactive Powder Concretes) v hydrotermálních podmínkách". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-433098.
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The diploma thesis deals with the study of hydration of reactive powder concrete under hydrotermal conditions. The theoretical part describes the properties of materials and additives used for the preparation of mixtures. The following describes the principles and requiments for the materials for preparing the reactive powder concrete. The practical part is studied design method mix and the impact of materials to the consistency of paste. The effect of cample placement on flexural and compressive strength of the prepared mixtures was observed. The samples were stored under standart laboratory conditions and under hydrothermal conditions. The phase composition of the samples was monitored by X-ray diffraction analysis and the mocrostructure by scanning electron microscopy.
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Ondráček, Michal. "Vývoj vysokopevnostních betonů definovaných vlastností s využitím druhotných surovin". Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-233787.
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Civil engineering development is connected with the application of new construction methods and the development of new building materials. Concrete, as one of the basic building materials, is part of this development. A major turning point in the development of concrete and its properties occurred with the use of new, more efficient plasticizing additives. This allowed to produce concrete with lower water cement ratio, while increasing the strength of concrete. Gradually, the compressive strength of concrete boundary has moved by several levels, when there are currently commonly used concrete with strength of about 100 N/mm2 and with the special methods of concrete production strength range from 250 to 300 N/mm2. A negative aspect of the development of (ultra) high-strength concrete is their energy and economic demands. A characteristic feature of high-strength concrete is a high content of cement and very fine admixtures, especially silica fume. One way to improve the economics of these types of concrete is the application of cheaper admixture based on industrial waste. The content of this work is the observation and description of the properties of high-strength concrete and reactive powder concrete, in which the admixtures were based on industrial waste were applied. Part of this work is the comparison of economic parameters for individual types of concrete.
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Behloul, Mouloud. "Analyse et modélisation du comportement d'un matériau à matrice cimentaire fibrée à ultra hautes performances : bétons de poudres réactives, du matériau à la structure". Cachan, Ecole normale supérieure, 1996. http://www.theses.fr/1996DENS0026.
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L'objectif de ce travail est d'étudier le comportement mécanique des bétons de poudres réactives renforces de fibres métalliques (bpr) et de définir des modèles de calcul permettant la prédiction du comportement des structures en bpr. Le comportement du bpr sous différentes sollicitations: compression, traction et flexion est présenté dans un premier temps. Ensuite, la distribution des fibres dans les structures est étudiée et son aspect aléatoire quantifié ; une formulation empirique de sa dispersion est proposée. Cet aspect aléatoire de la distribution des fibres est intégré dans un modèle probabiliste. Ce modèle, base sur la loi du maillon le plus faible, permet de rendre compte du comportement de structures sollicitées en traction directe. Une approche continue permettant la prédiction du comportement des structures fléchies est développée. La loi de comportement représentative intervenant dans ce calcul est obtenue en utilisant le modèle probabiliste. Enfin, l'ensemble de cette approche est validée sur des structures de différentes tailles, précontraintes et non précontraintes
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Bonneau, Olivier. "Étude des effets physico-chimiques des superplastifiants en vue d'optimiser le comportement rhéologique des bétons à ultra-hautes performances". Cachan, Ecole normale supérieure, 1997. http://www.theses.fr/1997DENS0027.
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Les bétons de poudres réactives (BPR) forment une nouvelle génération de BUHP. Les bpr sont composes de poudres fines et sont caractérises par un faible rapport eau/ciment et une forte concentration en superplastifiant. Pour étudier l'interaction (ciment, fumée de silice, adjuvant), nous avons développé une méthode basée sur le découplage des effets de l'eau et de l'adjuvant sur la rhéologie. Dans le cas des bpr, il existe un optimum rhéologique en superplastifiant qui dépend fortement de la formulation. Un modèle de prédiction permet de calculer cet optimum avec seulement 4 paramètres définissant la composition du bpr. Des essais d'isothermes d'adsorption confirment le rôle de ces paramètres. Ainsi, la quantité d'adjuvant pour saturer les surfaces est proportionnelle au dosage conduisant au comportement rhéologique optimal. Les effets du superplastifiant sur la cinétique d'hydratation sont étudiés par l'intermédiaire de la conductivité électrique et de la puissance dissipée lors d'essais en mode isotherme. Nous avons mis en évidence une relation linéaire entre la conductivité électrique (#e#l#e#c) et le degré d'hydratation () : #e#l#e#c = av + bvx. Le terme BV est une caractéristique de l'empilement granulaire des bpr étudiés. Le seuil de percolation électrique peut être observé sur cette courbe, #e#l#e#c
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Fávero, Rafael Burin. "Caracterização mecânica de material compósito cimentício avançado à base de pós reativos". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/156365.
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O compósito de pós reativos é um material formado basicamente por uma argamassa de matriz cimentícia ricamente refinada em termos de granulometria e com a inclusão de fibras, como forma de reforço. Entretanto, duas características principais o definem em termos de composição: a quase ausência de armaduras em estruturas construídas com o material e o fato de dispensar o uso de agregados com diâmetro máximo superior a 1 mm, sendo constituído basicamente por pós. O CPR possui características únicas que lhe conferem resistências à compressão de seis a oito vezes superiores ao concreto convencional, e tração e flexão cerca de dez vezes maior, podendo competir diretamente com estruturas em aço. As dificuldades para sua obtenção e utilização residem no fato de ser um material que demanda grande precisão em sua dosagem e também nos custos diretos para sua produção, bem como o desconhecimento em relação ao seu desempenho. O presente estudo comparou três diferentes traços de CPR a um traço de concreto convencional de uso comum na indústria de préfabricados, de forma a caracterizá-lo mecanicamente e buscando viabilizar sua produção e aplicação na indústria de pré-fabricados nacional, utilizando cinza volante como alternativa de aglomerante e a hibridização de fibras. Efetuou-se também um estudo comparativo dos custos de sua obtenção em relação ao concreto convencional, levando-se em conta o desempenho mecânico. Os resultados indicam que para todos os traços estudados, em relação ao concreto convencional estabelecido como parâmetro, as principais propriedades mecânicas contemplam uma resistência à compressão até quatro vezes superior; módulo de elasticidade longitudinal 50% superior; resistência à tração na flexão até sete vezes superior e resistência à tração direta cerca de três vezes superior. Com relação aos custos, ao se considerar o seu comportamento mecânico, o CPR se mostrou mais competitivo frente ao concreto convencional, demonstrando que a sua implantação, dentro da indústria de pré-fabricados nacional, pode e deve ser explorada.Reactive powder composite is a material formed by a richly refined cementitious mortar matrix in terms of grain size and the inclusion of fibers, such as reinforcement. However, two main features define it in terms of composition: the almost absence of reinforcement steel and the use of aggregates with a maximum diameter greater than 1 mm, consisting basically by powder materials. RPC has unique characteristics which confer compressive strength six to eight times higher than conventional concrete and tensile and flexural strength about ten times higher, and may compete directly with steel structures. Difficulties in obtaining and use the material lie in the fact that it requires a great precision in the dosage and also the direct costs for its production, as well as the lack of knowledge about its performance. This study compared three different CPR mixes to a conventional concrete mix, commonly used in the precast industry, in order to characterize it mechanically and intending to disseminate its production and use in the national precast industry by using fly ash as a binder and alternative fiber hybridization. It also made a comparative study between the costs of obtaining CPR compared to conventional concrete, taking into account the mechanical performance. The results indicate that for all mixes studied in relation to conventional concrete set as a parameter, the primary mechanical properties include a compressive strength up to four times higher; longitudinal elastic modulus exceeding 50%; bending tensile strength up to seven times and resistance to direct tension about three times higher. Considering the costs compared to the mechanical behavior, CPR was found more competitive against the conventional concrete, demonstrating that its implementation within the national precast industry can and should be explored.
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Wu, Chien-Hsing y 吳建興. "Durability of Strengthening Concrete Members Using Reactive Powder Concrete". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/343247.
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碩士朝陽科技大學
營建工程系碩士班
91
Taiwan is located in the Pacific earthquake region, not only the frequency is very high, but the weather here hot and humid, changeful the weather, cracks or damage of concrete members will occur as a result of a number of internal and external factors in concrete structures, the safety of building deeply affected by it. In this study, reactive powder concrete（RPC）is used to investigate the durability of strengthening concrete members. In the first place, testing for mechanical properties of RPC. Secondly, evaluate the durability of RPC by accelerating carbonation test and seawater dry-wet cycle acceleration deterioration test. The test included compression strength, bending strength, slant shear strength, splitting tensile strength, pull out strength, ultrasonic wave propagation velocity measurement, abrasion test, chloride ion penetration test, carbonated depth measurement, X-ray, and SEM observation etc. In the last of this thesis, two different materials are evaluated with their reinforced effect and cost. It is expected that this studies and tests will be helpful to the strengthening of the damaged building structures. The test results show that the mechanical properties of reactive powder concrete possess high strength, toughness, and abrasion resistance. At the accelerated carbonation test, no carbonation could be detected on reactive powder concrete samples. After seawater dry-wet cycle test exposures, there is no influence on strength and microstructure. The RPC displays excellent durability and penetration resistance. Using RPC and carbon fiber reinforcement polymers （CFRP） on strengthening concrete members could be obtain excellent retrofit effects, but their material costs are extremely different.
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Liao, Shu-Lin y 廖書麟. "Autoclaved Curing Process of Reactive Powder Concrete". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/53972723467904146891.
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Hsieh, Mo-Han y 謝孟翰. "Impact Mechanics of Reactive Powder Concrete and High Performance Concrete". Thesis, 1999. http://ndltd.ncl.edu.tw/handle/05133229681265823781.
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碩士國立臺灣大學
土木工程學研究所
87
In this project, experimental and analytical study focused on the impact mechanics of two types of concrete. One is the High Performance Concrete (HPC), and the other is the Reactive Powder Concrete (RPC). After adding a proper amount of steel fiber, HPC becomes Steel Fiber Reinforced Concrete (SFRC). SFRC is also considered in our study. Limited by the size effects from the concrete specimens, combination of Direct Impact Method (DIM), and Transient Laser Doppler Anemometer (TLDA), was used to develop a new analytical approach called Stress Gradient Direct Impact Method (SGDIM). SGDIM is able to fully describe true mechanical behaviors of the concrete specimen under impact loading. Our experiment also progressed on the laboratory verification of the SGDIM and the result showed that it is more appropriate to use such theoretical model to analyze the mechanical behavior of concrete under impact loading. This study started with the investigation of static and dynamic compression testing of the concrete specimens. The result from the static compression testing indicated that the addition of steel fiber increased the compressive strength of the RPC specimens; however this observation was not profound with HPC and SFRC specimens. The result from the dynamic compression testing indicated that the failure criterion is the initial input energy to the specimen. Moreover, the absorbed energy of RPC specimen causing failure was about equal to the corresponding energy level of its modulus of toughness. The ratio of dynamic compression strength to static compression strength decreases as percentage of steel fiber in specimen increases. Under the same initial input energy, the experimental results showed that more energy can be absorbed by SFRC than HPC. It was also observed that the SFRC has lower percentage increase in compression strength than HPC. The static and dynamic fracture toughness testing of the RPC specimens were also completed. The result from the testing shows that the addition of steel fiber increases the specimen''s resistance to fracture, but it does not affect RPC''s static and dynamic fracture toughness. Through our experimental design, the fracture toughness value (KId) of RPC was found to have increased as fracture toughness rate increases. The concrete impact dynamic properties obtained from this research, including characteristics of energy absorption, resistance strength to dynamic compression, dynamic stress-strain relation, fracture mechanics, and failure criteria, can be used as future references to related engineering applications.
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Pan, Wei-Bang y 潘偉邦. "The Study of Reinforced Concrete Beam Retrofitted by Reactive Powder Concrete". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/15277200461879663500.
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碩士朝陽科技大學
營建工程系碩士班
102
The main purpose of this study is to evaluate the performance testing of reinforced concrete beam retrofitted by using reactive powder concrete. It will significantly reduce cost to maintain aged building structures and provide longer durability if the test proves great effectiveness by using reactive powder concrete to repair. Furthermore, it provides a case study in reference for structure repair. The major topics are summarized as follows: 1.The feasibility of reactive powder concrete as repairing material assessed by using basic mechanical tests. 2.Investigating the repair and cost effectiveness of reinforced concrete beams retrofitted by reactive powder concrete and carbon fiber reinforced plastic (CFRP) material. The result showed that reactive powder concrete and ordinary concrete have Poisson’s ratio between 0.19 and 0.21, they have great compatibility. Hence, reactive powder concrete might suitable for cement mortar or concrete repair. The ultimate load increased 35% by reactive powder concrete and it increased 56.6% by CFRP retrofitted in small-size reinforced concrete beam test. However, the amount of displacement increased only 4 mm by CFRP retrofitted as compared with the use 1% and 2% steel fiber of reactive powder concretes increased 15.7 mm and 26.8 mm, relatively. Furthermore, the repair price on each m2 of reactive powder concrete is twice as cost effective as one layer of CFRP. Therefore, reactive powder concrete has better durability, reinforced displacement and toughness as compared to CFRP and it is suitable for concrete structure repair.
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Malik, Adnan Rauf Civil & Environmental Engineering Faculty of Engineering UNSW. "An investigation into the behaviour of reactive powder concrete columns". 2007. http://handle.unsw.edu.au/1959.4/40663.
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The research reported in this thesis was carried out in two phases to investigate the behaviour of reactive powder concrete (RPC) columns. In the first phase of this study, six steel fibre reinforced RPC columns of 150 mm square cross section were tested to failure under various loading eccentricities. The RPC mix contained 2 percent (by volume) of straight steel fibres with a concrete strength of about 150 MPa. The columns contained either 4 or 7 percent of longitudinal reinforcement but no tie reinforcement in the test region. All the columns failed in a controlled manner and no buckling of the longitudinal steel or cover spalling was observed, even well beyond the peak load. The tests revealed that stirrups can be significantly reduced for steel fibre reinforced RPC columns, which could lead to an increase in the speed of construction with an associated potential reduction in construction costs. In the second phase, 17 RPC columns were tested with 16 confined using carbon fibre reinforced polymer (CFRP). The concrete mix contained either no fibres or 2 percent (by volume) of straight steel fibres with concrete strength of approximately 160 MPa. The columns contained no conventional steel reinforcement. For the concentrically loaded specimens, failure occurred at or close to the peak loading and the CFRP increased the strength by 19 percent compared with the unconfined specimen. The tests showed that the formulae developed to predict the peak strength of concentrically loaded FRP confined conventional strength concrete columns, in general, overestimate the load carrying capacity of FRP confined RPC specimens. The CFRP was shown to be effective in controlling the failure for the eccentrically loaded specimens. There was no evidence, however, that the use of CFRP in the hoop direction significantly increased the strength of the columns. Three dimensional nonlinear FE analyses of the test specimens were undertaken using the program DIANA. The FE analyses showed a reasonable comparison with the experimental results for the specimens tested under eccentric loading.
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Hung, Chi-Che y 洪啟哲. "Reactive Powder Concrete Using Materials with High Aluminum Composition". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/18211054893019773218.
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碩士國立臺灣海洋大學
河海工程學系
92
In this study, we try to improve the early strength, fire resistance and work construction convenience of the traditional Reactive Powder Concrete (RPC for short) that uses materials containing high silica. Although the traditional RPC has ultra-high compressive strength, high bending strength, excellent corrosion prevention ability, good performance under impacting and excellent durability, it still has some drawbacks such as exerting pressure before hardening, high-temperature curing after hardening, long duration for strength development and low fire-resistance due to type II cement it uses. The goal for this study is to develop a RPC having an easy construction convenience, high early strength and good fire resistance as well as keeping the merits for the traditional RPC. To reach such a goal, the materials containing high aluminum are used. In addition, solid powder additives are used which is for sure to be more convenient. The results indicate that the RPC using high aluminum materials keep the merits of the traditional RPC using the common curing condition. For example, the 28-day compressive strength can reach 184 MPa, the elastic modulus can reach 66 GPa, the water absoption can be lower than 0.94%. From the mechanical properties, physical properties and durability, RPC using high aluminum materials is a high performance material and it is promising in the future.
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Cheng, Ching-Hung y 鄭慶鴻. "A Study of Reactive Powder Concrete at Elevated Temperatures". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/51772824955669444485.
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碩士國立臺灣大學
土木工程學研究所
89
Abstract This study is based on the material phase. Three methods were applied to control thermal spalling. These are, adding polypropylene fibers, high alumina cement replacement and changing curing regimes. A heating rate of 2.5℃/min was adopted to heat cylindrical specimens with 10cm in diameter and 20cm in length up to 500℃. The first aim is, with the prerequisite of non-spalling, to find the least polypropylene fiber content, high alumina cement replacement and the maximum moisture content. The mechanism of spalling was explained and compared with that of high performance concrete from a macro point of view such as the measurements of pore pressures and temperature distribution as well as a microstructural analysis, which is, nitrogen BET method. When spalling is controlled, the residual mechanical properties after heating up to 500, 700, and 900℃ were measured. At last, we gathered statistics of probability of spalling and evaluated the three anti-spalling methods. Test results showed that: 1.The least polypropylene fiber content is 0.20% by volume; the least high alumina cement replacement is 50% by weight; the alternate curing regime is one day of wet curing at 90℃ and 6 days of dry curing at 110℃. 2.The spalling of RPC is repeated, local, and begins at the points with higher temperatures. 3.The property of spalling timing was observed as other concretes. It is 300~350℃ (furnace temperature) for the first spalling. All spalling occurred at 300~450℃. The timing of spalling coincides to the timing of maximum pore pressures and thermal differences. 4.The main cause of thermal spalling is confirmed to be the pore pressures. 5.The characteristics of spalling and distribution of pore pressures are quite different from those of high performance concrete. There showed little differences on distribution of temperatures. 6.Non-uniform pore shapes, very little pore volume and pore diameters were observed by nitrogen BET method. This has adverse effects on anti-spalling. 7.RPC after heating to 900℃ could not be used for structural purposes. Keywords: Reactive powder concrete, polypropylene fibers, high alumina cement, thermal spalling, nitrogen BET method.
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Liu, Hsuan-fu y 劉宣甫. "Dynamic Analyses of Fiber-Reinforced Reactive Powder Concrete Plates". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/66515855694729445582.
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碩士國立成功大學
土木工程學系碩博士班
95
Because the impact problems receives the widespread attention gradually and the computer technology refresh so quickly, the research of impact are not only about experimental stage. With the finite element analysis software appearance, enables the numerical simulation to achieve the top situation. In this study, the most important goal is to consider the behavior of materials truly and propose more reasonable nonlinear analysis model. Use the finite analysis software “ABAQUS” to establish the model of aluminum plate and concrete plates with low speed impact and compare with the true experiment.
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Chen, Sheng-Jie y 陳勝傑. "Research for the pozzolanic material in Reactive Powder Concrete application". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/ex5hhh.
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碩士國立中山大學
海洋環境及工程學系研究所
103
This research explores the engineering properties of reactive powder concrete (RPC) with the following mixtures: The following mixtures of research: (1) replacing the weight of silica fume ( 30 %, 50 %, 70 %) by slag. (2) replacing the weight of cement ( 7 %, 10 %, 15 %,20%,30%) by zeolite. (3) replacing the weight of cement ( 10 %,20%,30%) by slag. (4) Integrated replacing the weight of silica fume ( 30 %, 50 %, 70 %) by slag and replacing the weight of cement (10 %,20%,30%) by zeolite. The results show that：(1)The effects of replacing silica fume by slag on workability have positive impact;(2) The test results of ultrasonic pulse velocity and electrical resistance for RPC show that RPC has good durability and corrosion resistance;(3) The test results of water absorption in each group under a suitably substituted to reduce the overall amount of water absorption is helpful;(4) The test results of compressive strength shows the pozzolanic materials used in RPC has a positive effect. In each group, only the ratio of replacing the weight of cement (20%,30%) by zeolite have significantly lower. Other the ratio of high quartz content is has significantly lower in high substitution of silica fume.
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Yang, Hong-Bin y 楊泓斌. "Use of Ceramic Materials as Aggregates in Reactive Powder Concrete". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/05432486974901655848.
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Chen, Han-Hao y 陳漢豪. "Effect of Autoclaved Curing Process on Reactive Powder Concrete Behavipr". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/19857620458963542801.
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YU-HSIEN, FAN y 范毓賢. "Metel Reinforced Reactive Powder Concrete Composite Plate Ductility dissipation behavior". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/65346547431974137627.
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Kannangara, A. M. U. Thathsarani. "The Behaviour of Reactive Powder Geopolymer Concrete at Elevated Temperature". Thesis, 2018. https://vuir.vu.edu.au/37855/.
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Concrete is one of the most widely used materials within the construction industry due to its versatility, durability, superior mechanical properties and excellent resistance to fire. In addition to this, the rapid growth in population and urbanisation has accelerated the demand for high strength concretes. However, high strength concretes suffer a condition called spalling when exposed to elevated temperature levels which is associated with the breaking away or exploding of concrete layers due to the internal stresses. Additionally, concrete is a material having a very high carbon footprint mainly due to its binding material, cement, which is reported to be the second largest emitter of carbon dioxide.
These issues have driven researchers to experiment alternative materials which can better benefit the economy and the environment. Studies show that blended concretes, which use supplementary cementitious materials such as slag, fly ash, silica fumes in partial replacement to cement and Geopolymer (GP) concretes, which eliminate cement usage altogether, display a high degree of resistance to fire. Additionally, these materials are further deemed worthy due the reduction or elimination of cement making it a more sustainable material.
This study focuses on the fire performance of GP pastes, reactive powder concretes (RPC) and a newly developed GP paste based reactive powder concrete called reactive powder GP concrete (RPGC). RPGC was produced using class F fly ash and sodium-based activators in relation with silica fumes and micrometre aggregate. The study investigates properties such as workability, setting times, density, compressive strength, residual strength, thermal cracking and mass loss under controlled laboratory conditions. The study further investigates the performance of GP paste specimens of varied sizes subjected to different curing conditions. A comparison on the properties of two fly ash materials, namely Gladstone fly ash and Gladstone/Callide fly ash are also presented.
Both types of fly ash displayed high early strengths and exceptional fire performance with a maximum strength gain of approximately 45% after an exposure to 400oC. RPC on the other hand exhibited high levels of explosive spalling at a temperature of around 360oC despite initial compressive strengths reaching a maximum of 140.7 MPa at 7-day testing. RPGC displayed good workability conditions with a maximum of 252 mm and a minimum of 187.5 mm, whilst achieving an initial compressive strength of 76.3 MPA at 24-hour testing. Furthermore, RPGC resulted in the lowest degree of thermal cracking with majority of the specimens having no visible cracking even after an exposure of 800oC. Moreover, RPGC recorded the lowest percentage mass loss amongst all experimented specimens.
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Du, JYUN-YING y 杜俊穎. "Steel Fiber in Autoclaved Condition on Reactive Powder Concrete Stiffening Mechanism". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/52609989771485945135.
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Lee, Kun-Long y 李坤龍. "Study of Making the Ditch Cover with Reactive Powder Concrete (2)". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/00666646382214715184.
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碩士朝陽科技大學
營建工程系碩士班
96
To improve the common shortcoming of the ditch cover, including weight, unit price, and loading capacity, we try to change the steel fiber volume content (2.5% , 3%, and 3.5%), with the different specification of steel fiber (0.20mm and 0.25mm in diameter). The study mainly discusses the reactive powder concrete (RPC) in economical viewpoint, high loading capacity, freeze-thaw cycles tolerance, and free-falling test, and simulates the destruction of the steel fiber with high loading by ANSYS analysis. By numerous experiments we find the ditch cover with capable of bearing vehicle weight. It assumes that the loading capacity of a ditch cover is 10 tons if the vehicle weight is distributed equally among all tires. Compared with the ditch cover with FRP glass fiber sold in the market, the experimental result shows the RPC ditch cover containing 2.5% steel fiber content is reached the predetermined effect, and remains good condition on the front view after the free-falling test. After freeze-thaw cycles the loading capacity of the RPC ditch cover has evidently enhancement, besides bearing at least 10 tons after the loading capacity test. As a result, an appropriate ratio of RPC applied in the material of ditch cover has been obtained, the above study would provide a reference manufacturing for the RPC ditch covers.
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Lin, Yu-Cheng y 林育承. "A Study on the Reactive Powder Concrete Using Silica-Based Materials". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/66635970160547064291.
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碩士國立臺灣海洋大學
河海工程學系
102
This study is an application of Boundary-Point-Matching Method (BPMM). We use BPMM to solve problems of an Infinite Domain containing Cylindrically Orthotropic and Functionally Graded Multi-Inclusion. Our study acquires the general solution of Laplace equation from the solution of Cylindrically Orthotropic and Functionally Graded Multi-Inclusion. Moreover, we obtain the general solution of control equation from the solution of Cylindrically Orthotropic and Functionally Graded Multi-Inclusion. In our study, we take two problems of electrostatic fields and antiplane elastic as cases, and attempt to solve these problems through simultaneous equation established from BPMM. The results of simultaneous equation are consistent with the results of recent research.Finally, we abstract a brief summary from organizing, analyzing, and discussing our research results. Keywords: Electrostatic fields; Antiplane elastic; unctionally Graded; Cylindrically Orthotropic
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Liang, Tsai-tung y 蔡東良. "Fundamental Investigation on Mechanical and Setting Behavior of Reactive Powder Concrete". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/02412363542766291110.
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碩士國立高雄第一科技大學
營建工程所
95
This research was regarded as the preliminary research of one-series researches on developing high-performance patching material for urgent retrofitting. Generally thought, the features of the concrete used for urgent retrofitting are requested with high strength, short setting-time as well as good workability, etc. Reactive Powder Concrete (RPC) is known for its excellent mechanical properties .As a result, this research was motivated to exploit RPC as the high-performance patching material. Setting-time is one key flag to evaluate the workability of RPC. It is mainly related to the hydration degree of RPC. Because some research indicated there exists evolutionary relationship between concrete resistivity and hydration degree of concrete, this research attempted to measure electronic resistivity of concrete to correlate the hydration degree of concrete; then estimate the setting-behavior of RPC by the electronic resistivity. In order to investigate the relations between the compressive strength, the settime and the mixing-proportion, water/cement ratio, binder/cement ratio and silica fume/cement ratio were selected as the experimental variables. Through orthogonal array of the experimental design, 27 groups with 81 RPC specimens were prepared for experiments. For effectively and simplifying the measurement procedure for concrete setting-time, this research simultaneously utilized the electronic resistivity and penetration-resistance test to estimates setting-time. Traditionally, the setting-time of OPC can be estimated according to the penetration-resistance test by measuring the concrete surface strength. By comparing the setting-time obtained by the electronic-resistivity meter the penetration-resistance test, the feasibility of electronic-resistivity meter for measuring setting-time of OPC was discussed. In this research, through multiple-range analysis, ANOVA and F test value, it can be thought that the mixing-proportion factors are directly related to the compressive strength and setting-time because the measured electronic resistivity and the conductivity of ions in RPC are observed to have the reciprocal relation. Through the comparisons, the setting-time individually obtained by penetration-resistance test and by electronic-resistivity meter show high agreement, which reveals the electronic-resistivity meter can be potentially used as one alternative of laboratory methods on measuring setting-time of cementations material.
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Chen, Jhin-Hong y 陳志宏. "Hydraulic Structures made by Reactive Powder Concrete Containing Blast Furnace Slag". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/90018948707557045061.
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碩士國立高雄應用科技大學
土木工程與防災科技研究所
103
Compressive stress of concrete used in hydraulic structures is 21 MPa usually in Taiwan. This kind of flood control structures is hard to resist the abrasion by water with sand and gravel. Meanwhile, hydraulic structure is easy to induce cracks in concrete due to earthquake. In this research, reactive powder concrete (RPC) with 150MPa is applied to hydraulic structure. The properties of RPC were investigated by using slag to replace partial silica fume and adding 1% and 2% steel fibers. Those properties include compressive strength, flexural strength, fracture toughness and shear strength with and without water contents. Dynamic compressive strength, impact resistance, volume abrasion, freezing and thawing resistance were also conducted. Results show that the compressive strength and shear strength of RPC containing water are always lower than those of without water, nevertheless, elastic Young modulus has less effective to water content. In addition, flexural strength of RPC containing water is higher that without water. Fracture toughness of RPC is at least three times higher than that of normal concrete. While steel fibers were added to RPC, fracture toughness increases two times more. Hence, to increase impact resistance of hydraulic structure, RPC had better add proper steel fibers. To design hydraulic structure made by RPC, the shear strength is suggested to deduct 20% at least. RPC has a higher resistance of volume abrasion, only 30% volume abrasion of normal concrete. RPC with partial slag replacements also owns high freezing and thawing resistance.
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Lou, Iok-Un y 盧毓源. "Feasibility Study of Reactive Powder Concrete Applied in Superstructure of Bridges". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/18899956713908532519.
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碩士國立臺灣大學
土木工程學研究所
104
The reactive powder concrete (RPC) was first published by French in 1994 and it had been widely applied in bridge engineering in advance countries such as Europe and Japan due to its great properties. In Taiwan, the climate is hot and humid and it would deteriorate the old structure rapidly. On the other hand, Taiwan is highly developed area and lack of land resource. If we applied RPC in superstructure of bridges, both the member section and the self weight would be reduced. Simultaneously, the low permeability can inhibit the chloride attack and prolong the service life of the bridge. This study is divided into two parts. The fisrt part will find out the mechanical properties and durability properties of RPC. The conclusion of mechanical properties of RPC is that under high temperature(90℃) curing, the strength can reach the optimal value at age of 7 days. On the other hand, under room temperature curing, the compressive strength will increase with the increasing curing period and will reach the same strength as that under high temperature curing. The development of strength will slowed down after the age of 56 days and the performance between high temperature and room temperature will reach the same level at age of 90 days. In addition, the conclusion of durability properties of RPC is that the performances in both stability of volume and the compactness of internal structure are better compared with the performaces of OPC. It is contributed to the accelerated hydration and pozzolanic of RPC under high temperature curing, which reduce the water loss and form a dense internal structure in a short period. At the same time, adding steel fiber can also increase the internal bonding strength to keep its volume stable. Secondly, the material parameters of RPC obtained in the first part are used to design a superstructure of bridge and check whether the superstructure passes the recommendation adopted in Taiwan. According to the recommendation adopted in Taiwan, the loading, the prestressed losses and ultimate capacity are calculated, and it is showed that the prestreesed loss of RPC superstructure is of better performance than the one with OPC. Also, applying RPC can reduce the size of section and self weight. Finally, the original mix proportion is adjusted and the possibility of the precast segmental method is also evaluated. Moreover, a real size specimen is casted and tested in this study. The accuracy of the analysis of the design is reserved.
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Lin, Shu-Lan y 林淑蘭. "Study of Fire-Damage and Freeze-Thaw of Strengthening Concrete Members Using Reactive Powder Concrete". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/19923397464864178210.
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碩士朝陽科技大學
營建工程系碩士班
93
Abstract In this study, reactive powder concrete（RPC）was used to investigate the effect of strengthening concrete members by fire-damage test and freeze-thaw test. At first, the physical and mechanical properties of RPC were tested. Secondly, evaluate the durability of RPC by fire-damage test and freeze-thaw test. The tests included compressive strength, flexural strength, splitting tensile strength, tensile strength, and slant shear strength etc. Their reinforced effect was evaluated and analyzed by different repair material and different thickness, such as plain concrete and RPC with different amount of fibers. It is expected that this studies and tests will be helpful to the strengthening of the damaged building structures. The results show that the mechanical properties of RPC possess high strength, toughness, and abrasion resistance. It could be detected in the fire-damage test at the temperature of 400 ℃ above and fire duration of 2 hours which cause explosion of RPC. There is no damaged influence on strength and abrasion after the freeze-thaw test. The RPC displays excellent durability and freeze-thaw resistance. The RPC2 with 2-cm thickness on strengthening concrete members could be obtained excellent retrofit effects.
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Chen, Yu-Sung y 陳佑松. "Durability of Fire-Damage and Freeze-Thaw of Strengthening Concrete Members Using Reactive Powder Concrete". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/mft873.
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碩士朝陽科技大學
營建工程系碩士班
94
In this study, reactive powder concrete（RPC）was used to investigate the effect of strengthening concrete members of durability by fire-damage test and freeze-thaw test. In the first place, the mechanical properties of RPC were tested. Secondly, evaluate the durability of RPC by fire-damage test and freeze-thaw test. Their effects were evaluated and analyzed by different curing temperatures (room temperature and high temperature), different repair materials and methods, and RPC with different amount of fibers. At last, the strengthening comparison of RPC and different repair materials was evaluated by fire-damage test and freeze-thaw test. It is expected that this studies and tests will be helpful to the strengthening of the damaged building structures. The test results show that the mechanical properties of reactive powder concrete possess high strength and toughness. It could be detected in the fire-damage test at the temperature of 400 ℃ above and fire duration of 1 hour which cause explosion of RPC. There is small damaged influence on strength at 600 freeze-thaw cycles. The results from 28-day compressive strength show no difference, while RPCs were cured by room temperature and 90 ℃temperature. The RPC displays excellent freeze-thaw resistance. The RPC with 1.5-cm thickness on strengthening concrete members could be obtained excellent retrofit effects. Using RPC, carbon fiber reinforcement polymers （CFRP）and steel plate on strengthening concrete members could be obtain excellent retrofit effects, but their material costs are extremely different.
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Shih, Li-Wai y 石立暐. "The probe of reactive powder concrete under repeated loading by fiber optics". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/15142054221839240439.
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Wu, Chung-sheng y 吳崇聖. "Study on Properties of Reactive Powder Concrete with Fly Ash and Slag". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/akms6y.
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碩士國立臺灣科技大學
營建工程系
94
This research discusses the properties of reactive powder concrete (RPC) with different replacing amounts of fly ash (15%, 30%, 45%) at 0% slag replacement, different replacing amounts of slag (10%, 20%, 30%) at 0% fly ash replacement and different replacing amounts of slag (0%, 12.5%, 25%) at 53% replacement of fly ash, at 25℃ and 85℃ curing temperatures. The experimental variances include slump flow, mechanical property, and durability. A control set of traditional RPC mix proportion was also used for comparison. The results show that: (1) The slump flow can achieve 190 mm and is better than the control set of traditional RPC mix proportion; (2) The mechanical properties of RPC by using water curing are more stable. Using fly ash and slag with steam curing can improve pozzolanic reaction and also get better mechanical property in early stage; (3) Using steel fiber can improve bending and splitting strength such that the RPC can have high strength and toughness, suitable for retrofit; (4) The test results of ultrasonic pulse velocity, electrical resistance and carbonation for RPC show that RPC has good durability and corrosion resistance; (5) Using RPC for retrofit can improve the strength of cylindrical specimen. The failure mode does not the pop-up flake due to the confining effect of steel fiber, and only some continuous cracks found on surface.
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Chiang, Chia-Ju y 江佳如. "Properties of Reactive Powder Concrete with Metakaolin Partially Replacing of Silica Fume". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/7stnhz.
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碩士淡江大學
土木工程學系碩士班
97
This research of reactive powder concrete (RPC) utilized the metakaolin and slag to replace the silica fume for 30%, 50% and 70% by weight. RPC specimens made and moisture cured at 23℃ and 70℃, respectively. Mechanical property tests and durability tests were conducted on those specimens. According to the research results, conclusions were summarized as follows: 1.Using constant-amount of water and superplasticizer, the results showed that the workability of the metakaolin replacement groups was worse than that of the silica fume (control) group. But the more the slag replaced the silica fume, the better its workability was. 2.The results showed that all the strengths of high-temperature (70℃) curing groups were higher than that of normal-temperature (23℃) curing groups due to the higher rate of hydration and pozzolanic reactivity of the RPC specimens. 3.The mechanical strengths of metakaolin and slag replacement groups were all lower than that of the control group, and the more it replaced the lower it got. Among them, the strengths of 30% replacement of metakaolin and 30% replacement of slag were the closest to that of the control and the most feasible. 4.The results indicated that the mechanical properties went higher with the age of the specimens, mainly because of the completeness of the hydration and pozzolanic reaction with longer age. 5.The surface resistivity of all RPC specimens was higher than the recommended value, 20 KΩ-cm. Some specimens were even higher than 300 KΩ-cm, which indicated good corrosion resistance and durability, after high-temperature moisture curing.
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Chung, Ming-Xuan y 鍾銘軒. "Mechanical and Physical Properties of Reactive Powder Concrete Using Aluminum Based Materials". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/e6ptxw.
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碩士國立臺灣海洋大學
河海工程學系
102
As time progresses,various field have begun to study nm,civil engineering also join the ranks of research,and the emergence of new materials. Due to advances in technology, in response to the different needs and developed the use of technology to traditional cement ground into particles generally more careful of ultra-fine cement, so that concrete is more dense, so that the project surname qualitative change, and can reduce the development of cement, reducing damage and pollution of the environment and resources of the planet. In this study, micro- fine cement, respectively, according to 0%, 10%, 20%, 30% the proportion of reactive powder concrete alternative high alumina in the alumina cement, the use of mechanical and durability properties to test. The study shows that 20% of the amount of substitution with optimum properties
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Hsiao, Yu-Chen y 蕭又禎. "The Preliminary Study of Making the Ditch Cover with Reactive Powder Concrete". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/19023264969189419391.
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碩士朝陽科技大學
營建工程系碩士班
95
The steel of demand has increased in recent years and the price of steel rises constantly. The economic worth of the steel retrieval by making the relevant products is very considerable, and so it causes a lot of thieves and some people who had little covetous psychology to have the stealing and selling behavior. It also causes the ditch cover made by cast iron to be stolen and jeopardize passersby and traffic safety. This research was focused in the further improvement shortcoming (including weight, unit price, and loading) of general ditch cover. The test parameters included the steel fiber content, the hole number and the thickness of ditch cover. To study the performance of reactive powder concrete on ditch cover, the 8 holes and 12 holes modeling test and the welded wire mesh were applied. The main process of experiment was in search of the ditch cover which enough bears heavy vehicle weight. The test load standard is 10 tons for the ditch cover that is the heavy vehicle average allocation with every tire in the experiment consideration. This study was to find the RPC ditch cover and also to compare with the casting iron ditch cover, the zinc grid ditch cover and glass fibre high polymer compound ditch cover on the market. The results show that adds 3% volume content of steel fibre, steel welded wire mesh and the 8 holes RPC ditch cover, the loading has already reached to the weight of all kinds of heavy vehicles. The results have also found out the suitable proportions of RPC for making the ditch cover.
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Chu, Shu Hsien y 朱書賢. "A Study of Interficial Properties of Steel Fiber and Reactive Powder Concrete". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/33654959388125200249.
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Yang, Jing-Cyuan y 楊景全. "Shear Behavior of Fiber-Reinforced Plastic and Reactive Powder Concrete Composite Components". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/45983628088248721620.
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Hong, Ji-bo y 洪健博. "Analysis of dynamic behavior of confined reactive powder concrete under high strain rate". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/90667321254461202703.
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碩士國立成功大學
土木工程學系碩博士班
96
The concrete is most widely used as the fundamental building construction material, so understanding the dynamic behavior of concrete under various conditions is an issue of great importance for applications in civilian and military engineering. In addition, the concrete material under the different strain rates and confinement effects, the behavior of mechanics is obviously different. Accordingly, this study examines the static and dynamic characteristics of reactive powder concrete by means of the commercial code – ABAQUS, including the following: In static analysis, develops a numerical model to examine the mechanics behavior under uni-axis and multi-axis stress about the reactive powder concrete. In dynamic analysis, the split Hopkinson pressure bar (SHPB) technique is used to study the dynamic mechanics behavior of material under uni-axis and multi-axis stress. Finally, the mechanics performance of the reactive powder concrete under the static and dynamic loading is summed up completely and the results of this study can be utilized as a reference in research and design.
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Lin, Yi-Zhen y 林宜貞. "A Study of Reinforcing Effect by Using Reactive Powder Concrete and Wire Mesh". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/84275050529396002041.
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碩士東南技術學院
防災科技研究所
94
The purpose of this study is to investigate the effects of confinement by using Reactive Powder Concrete（RPC）and wire mesh, together, to reinforce the compression member. The plain concrete specimen is used as the compression member. And three different reinforcing methods are used：1) one layer of wire mesh and 5mm thick of RPC, 2) two layers of wire mesh and 10mm thick of RPC, 3) three layers of wire mesh and 15mm thick of RPC. The RPC and wire mesh is placed at the outer ring of the plain concrete specimen to provide confinement to the specimen. The result of our study shows the compression strengths of the reinforced specimens increase 35﹪, 47﹪and 86﹪respectively, for each reinforcing method, when compared to the strength of the un-reinforced specimen. In addition to the increase in compression strength, the reinforced specimens also show a tremendous increase in ductility. For example, the length of the specimen decreases 20mm in compression test before failure occurred, if it is reinforced with three layers of wire mesh and 15mm thick of RPC.
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Peng, Jen-Po y 彭仁柏. "Static-Dynamic Toughness and Durability of Reactive Powder Concrete Containing Blast Furnace Slag". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/27077916763626818677.
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碩士國立高雄應用科技大學
土木工程與防災科技研究所
99
Reactive powder concrete (RPC) is a kind of ultra high strength concrete. Silica fume is always adopted in binders of PRC. To import silica fume is necessary in Taiwan will increase the cost of RPC. The cost down is possible if we replace parts of silica fume by blast furnace slag in RPC. The aims of this research are to investigate static and dynamic behavior, toughness and durability of RPC with target strength of 150MPa. Compressive strength, flexural strength, stress-strain curve, toughness index, strain energy, fracture toughness and direct shear strength were measured through MTS machine and split Hopkinson pressure bar (SHPB). The durability of RPC including accelerated carbonation test, chloride permeability test, sulfate resistance test and water permeability test was conducted. Results indicate that, the more silica fume replaced by blast furnace slag, the less compressive strength of RPC. Compressive strength can reach 150MPa for 50% silica fume replacement in RPC. Through high temperature curing at 210℃, RPC with blast furnace slag shows an increase in compressive strength, flexural strength and toughness. Adding 1% or 2% steel fiber into RPC can raise flexural strength and critical stress intensity factor KIC. Impact strength and energy-absorbing capability also increase with increasing strain rate and impact force. RPC containing blast furnace slag (HC) has better flexural strength and toughness compared with no blast furnace slag inside. For RPC containing slag, the degree of carbonation and the weight loss in sulfate were not significant. Moreover, chloride-penetration resistant capacity and water-permeability resistant capacity in RPC were better than those in common concrete. From SEM, RPC without slag shows more Monosulfoaluminates (AFm), but has more Ettringite (Aft) if slag is added.
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Lee, Chin-Hui y 李金輝. "THE STUDY OF REACTIVE POWDER CONCRETE BY USING HWANG-FULLER’S DENSIFIED MIXTURE DESIGN ALGORITHM". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/zpf8gk.
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碩士國立臺灣科技大學
營建工程系
94
This study is mainly applying Hwang-Fuller’s Densified Mixture Design Algorithm (HFDMDA) to reactive powder concrete (RPC) to replace traditional method. The parameters are 1) cement is included in packing; 2) cement is not included in packing but chemically balance cement and silica fume; and 3) chemically strengthening to achieve high early strength. The influences of pozzolanic material, such as fly ash and slag, of changing the paste quality, the maximum size of aggregate (Dmax), different h, curing temperature, and adding steel fiber on the property of RPC are explored. The test items include workability, compressive strength, bending strength, splitting tension, and dynamic modulus of electricity, dynamic modulus of rigidity, ultrasonic pulse velocity, electrical resistant, water absorption, drying shrinkage, chloride penetration, microstructure observation, etc. The results show by changing the mixing method can improve the workability of RPC. For hardened property, it shows the lower the water-to-binder ratio (w/b) and the higher the unit weight, the better the quality of RPC. The more the cement used the higher the early strength. The addition of steel fiber can improve the hardened property as expected. Under low w/b condition, the durability of all mixtures is similar. High temperature curing can improve early performance, but it is harmful to long-term property and durability of RPC.
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Wu, Chien-Chang y 吳建璋. "A Study on Engineering Properties of Reactive Powder Porous Concrete as Pavement Surface Course". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/54456353964955667621.
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碩士淡江大學
土木工程學系碩士班
95
Porous concrete is good at drainage, sound absorption and skid resistance, and is suitable for the hot and humid environment in Taiwan. Since its high air voids resulting in lower strength than conventional concrete, the range of application has limitation. Reactive powder concrete, however, has superior compressive and flexural strength. This study aims at combining the unique characteristic of porous concrete and reactive powder concrete, and to develop the reactive powder porous concrete (RPPC). RPPC has improved mechanical properties and performance, and hopefully will be an alternative of surface drainage material for the rigid pavement construction. Reactive powder mortar made of silica fume, crushed quartz, silica, superplasticizer sand and steel fiber was used in RPPC to improve strength and adhesion in this study. Concept of densest gradation packing was utilized to increase the strength of aggregate skeleton. Compressive strength, flexural strength and Cantabro abrasion tests were performed to examine the mechanical behavior of RPPC. Major findings based on the results of our tests are summarized as follows: 1. All groups of fresh porous concrete had large slumps except the control group. Our results showed that the more reactive powder mortar, the better workability. Also the larger nominal maximum size, the heavier unit weight. 2. Results of compressive strength test showed that RPPC using reactive powder mortar and high temperature curing had 28-day strengths greater than 280 kg/cm2. 3. Results of third-point loading flexural strength test showed that RPPC had 28-day flexural strengths greater than the design strength of 45 kg/cm2 and meet the target strength requirement of 52 kg/cm2 for national expressway. 4. Results of the permeability and British Pendulum tests showed that RPPC had good drainage and skid resistance. Cantabro abrasion test results showed that RPPC also had good abrasion resistance.
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Liao, Wen-Cheng y 廖文正. "The Study on Manufacture Processing and Toughness Behavior of Reactive Powder Concrete Thin Plate". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/90371720198690895107.
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Dong, S., D. Zhou, Ashraf F. Ashour, B. Han y J. Ou. "Flexural toughness and calculation model of super-fine stainless wire reinforced reactive powder concrete". 2019. http://hdl.handle.net/10454/17173.
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YesAs a type of excellent reinforcing filler, super-fine stainless wire (SSW) can form widely distributed network in reactive powder concrete (RPC) to transfer crack tip stresses as well as inhibit the initiation and propagation of cracks, leading to significant improvement of flexural toughness of RPC. In this paper, the flexural toughness of RPC beams and plates reinforced with 1% and 1.5% by vol. of SSWs was investigated, and its calculation model was established according to the composite material theory. Experimental results showed that the flexural toughness of unnotched beams fabricated with RPC containing 1.5% SSWs is 146.5% higher than that of control RPC without SSWs according to load-deflection relationships. The equivalent flexural strength of notched RPC beams is enhanced by 80.0% as SSW content increases from 1% to 1.5%. The limitation ability of SSWs on crack mouth opening can be used to evaluate the flexural toughness of composites. An addition of 1.5% SSWs leads to 201.9% increase of flexural toughness of RPC plates in accordance with load-deflection relationships. The calculation model based on the composite material theory can accurately describe the toughening effect of SSWs on RPC beams and plates. The enhancement of flexural toughness of RPC caused by SSWs is beneficial for improving the safety of structures as well as broadening the engineering applications of composites.
National Key Research and Development Program of China (2018YFC0705601) and China Postdoctoral Science Fundation (2019M651116).