Submitted by SBI Biblioteca Digital (sbi.bibliotecadigital@puc-campinas.edu.br) on 2017-03-23T12:34:35Z No. of bitstreams: 1 RENAN SERRALVO CAMPOS.pdf: 14804663 bytes, checksum: d21aa4db3ac6aef546c6f30dc795691b (MD5) / Made available in DSpace on 2017-03-23T12:34:35Z (GMT). No. of bitstreams: 1 RENAN SERRALVO CAMPOS.pdf: 14804663 bytes, checksum: d21aa4db3ac6aef546c6f30dc795691b (MD5) Previous issue date: 2017-02-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The high consumption of natural resources and energy, coupled with the significant amount of solid waste generated by the construction activities, makes this sector one of the most responsible for environmental impacts. The recycling of mineral fraction of construction and demolition wastes (CDW), in form of aggregates, is seen as an alternative to reduce these impacts. In this way, the aim of this study was to investigate the influence of recycled aggregates on the rheological, mechanical properties, physical indexes and surface finish of self-compacting concrete (SCC). For this, eight compositions of SCC were analyzed, using the Repette-Melo method and Alfred model, which is based on the concept of particle packing, for the mix design of concretes. Thus, two reference mixtures, composed only of natural aggregates, were established. The other mixtures used recycled fine and/or coarse aggregates instead of natural aggregates, at 20% by mass. The properties of fresh concrete were evaluated with respect to the flowability, viscosity (measure of the speed of flow), passing ability and segregation resistance. In hardened state, compressive strength, splitting tensile strength, static modulus of elasticity, water absorption by immersion and by capillarity, density and voids index were determined. In this study, rheological characterization of cement pastes and mortars destined to the production of SCC was also carried out using rotational rheometry. Rheological characterization of pastes, mortars and concretes is a suitable way to evaluate the behavior of these composites in fresh state, providing useful information that will aid in mix design process and quality control. Another property evaluated was the surface finish of concretes and mortars and the possible correlation of this with the rheological parameters. Through the results obtained it was possible to verify the loss of fluidity in mortars and concretes that used recycled aggregates. Regarding the mechanical properties, different behaviors were observed in concretes produced with recycled aggregates: those that were dosed by Repette-Melo method did not show a significant decrease of these properties; while the concretes dosed by the concept of particle packing exhibited a great reduction in mechanical properties. Concretes produced with recycled aggregates still showed an increase in water absorption by immersion, voids index and capillary absorption, when comparing to the respective reference mixtures. It was possible to observe a good linear correlation between surface finish and shear stress of mortars. In the case of concretes, the slump-flow was the property that best correlated with the quality of surface finish. / O elevado consumo de recursos naturais e energia, associado ao expressivo montante de res?duos s?lidos gerados pelas atividades de constru??o civil faz deste setor um dos maiores respons?veis por impactos ambientais. A reciclagem da fra??o mineral dos res?duos de constru??o e demoli??o (RCD), na forma de agregados, ? vista como uma alternativa para a diminui??o destes impactos. Isto posto, o objetivo deste estudo foi investigar a influ?ncia dos agregados reciclados nas propriedades reol?gicas, mec?nicas, ?ndices f?sicos e no acabamento superficial de concretos autoadens?veis (CAA). Para isso, foram analisadas oito composi??es de CAA, sendo empregados o m?todo de Repette-Melo e o modelo de Alfred, que tem por base o conceito de empacotamento de part?culas, para a dosagem dos concretos. Assim, foram estabelecidos dois tra?os de refer?ncia, compostos apenas por agregados naturais. As demais misturas utilizaram agregados mi?dos e/ou gra?dos reciclados em substitui??o aos agregados naturais, no teor de 20%, em massa. As propriedades do concreto fresco foram avaliadas no que diz respeito ao espalhamento, tempo de escoamento, habilidade passante e resist?ncia ? segrega??o. No estado endurecido foram determinadas as resist?ncias ? compress?o e ? tra??o por compress?o diametral, o m?dulo de elasticidade est?tico, a absor??o de ?gua por imers?o e por capilaridade, a massa espec?fica e o ?ndice de vazios. Neste estudo tamb?m foi realizada a caracteriza??o reol?gica das pastas de cimento e das argamassas destinadas ? produ??o dos CAA?s, por meio de reometria rotacional. A caracteriza??o reol?gica de pastas, argamassas e concretos ? uma forma adequada para avaliar o comportamento destes comp?sitos no estado fresco, podendo prover informa??es ?teis que auxiliar?o no processo de dosagem e controle de qualidade. Outra propriedade avaliada foi o acabamento superficial dos concretos e argamassas e a poss?vel correla??o deste com os par?metros reol?gicos. Atrav?s dos resultados obtidos foi poss?vel constatar perda de fluidez nas argamassas e concretos que empregaram agregados reciclados. No que tange as propriedades mec?nicas, foram observados comportamentos distintos nos concretos produzidos com agregados reciclados: ?queles dosados pelo m?todo de Repette-Melo n?o apresentaram decr?scimo significativo destas propriedades; enquanto que, os concretos dosados com base no conceito de empacotamento de part?culas exibiram grande redu??o nas propriedades mec?nicas avaliadas. Os concretos produzidos com agregados reciclados ainda apresentaram aumento na absor??o de ?gua por imers?o, no ?ndice de vazios e na absor??o capilar, quando comparados aos respectivos tra?os de refer?ncia. Foi poss?vel observar boa correla??o linear entre o acabamento superficial e a tens?o de cisalhamento das argamassas. No caso dos concretos, o di?metro de espalhamento foi a propriedade que melhor se correlacionou com a qualidade do acabamento superficial.

La thèse comprend 8 chapitres, 3 annexes, 191 figures, 43 tableaux, 13 photos et 181 références bibliographiques. Le corps du texte totalise 135 pages et les annexes 120 pages. Le chapitre 1 constitue lintroduction dans laquelle le contexte et les objectifs de la recherche sont définis. Le chapitre 2 présente létat de la question concernant les colonnes faites de tubes en acier remplis de béton (CFSHS columns - concrete filled steel hollow section columns). Leur comportement à température ordinaire et sous conditions dincendie est analysé ainsi que les paramètres significatifs qui guident leur comportement. Les propriétés du béton auto-plaçant sont aussi examinées dans ce chapitre. Le chapitre 3 est consacré à la présentation du code de calcul SAFIR développé à lUniversité de Liège pour la simulation du comportement structural à température ordinaire et sous conditions dincendie. Le logiciel a été utilisé pour simuler des résultats dessais expérimentaux présentés dans la littérature, et quelques calibrations sont proposées. En utilisant le modèle décrit au chapitre 3, la charge ultime à température ordinaire des colonnes CFSHS est calculée en considérant différents paramètres. On considère essentiellement des tubes de petites dimensions avec un pourcentage élevé darmatures ou contenant un autre profilé métallique. Ce type délément nest pas couvert par les Eurocodes. Des simulations ont été réalisées en vue dexaminer si les méthodes classiques de lEurocode 4 (EN1994-1-1) sont applicables à ce type de section et de voir quelle courbe de flambement est la plus appropriée. Le chapitre 5 décrit la recherche expérimentale réalisée à lUniversité de Liège relative au comportement au feu des colonnes CFSHS. Les essais expérimentaux ont été simulés par SAFIR, tant en ce qui concerne la répartition de la température à lintérieur des éléments que le comportement structural. Un des objectifs de ces calculs était de vérifier si les propriétés thermiques et mécaniques du béton auto-plaçant sont proches de celles du béton ordinaire. En vue de fournir aux bureaux détudes des outils pratiques de dimensionnement, une formule permettant dévaluer la résistance au feu des colonnes CFSHS est proposée dans le chapitre 6. Le domaine dapplicabilité a été étendu par rapport aux études précédentes. Une formule pour colonnes courtes de section carrée a dabord été établie sur base de simulations effectuées à laide de SAFIR en considérant linfluence des paramètres principaux. On examine ensuite si cette formule est aussi applicable à dautres types de profilés. La formule a été étendue en cas des colonnes élancées et à celui des colonnes chargées excentriquement. Létude expérimentale du chapitre 5 est limitée à des sections dassez petites dimensions (< 300 mm), essentiellement pour des problèmes de capacité de mise en charge des laboratoires. En vue de recueillir des informations pratiques pour des profilés de plus grandes dimensions pour lesquels on peut atteindre des résistances au feu de 2 heures et plus, des simulations numériques additionnelles sont présentées dans le chapitre 7, avec des résultats utilisables en bureau détudes. Le chapitre 8 donne les conclusions de létude et présente des suggestions pour des recherches futures.

Self-compacting concrete is an innovative construction material / its priority to normal vibrated concrete is that there is not any vibration requirement. Bond strength of reinforcement is one of the key factors that ensures the usefulness of any reinforced concrete structure. In this study, 6 full-scale concrete beams spliced at the mid-span were tested under two-point symmetrical loading. Test variables were bottom cover, side cover, free spacing between longitudinal reinforcement, lap-splice length and presence of transverse reinforcements within the lap-splice region. Specimen SC_22_44_88_800 had cover dimensions close to the code limits and had 36db lap splice length. This specimen showed flexural failure. Specimen SC_44_44_44_710 had 32db lap splice and cover dimensions greater than code minimums. This specimen showed yielding primarily. With the increasing loading, however, bond failure occurred with side splitting. ACI 408 descriptive equation for normal vibrated concrete predicted bar stresses of the unconfined specimens produced with self-compacting concrete acceptably well. The predicted values were lower than the measured values to be on the safe side. The error varied between 3.4% and 6.5%. All predictions of the ACI408 descriptive equation was higher than the measured bar stresses of the confined specimens produced with SCC. All the calculated values were unsafe. The error varied between 10.6% and 34.5%. Specimen SC_44_22_22_530_T4 with 24db lap splice length had side cover and spacing between bars 63.3% and 56.7% less than the ACI 318 limits. The calculated bar stress was 21.6% higher than the measured value. The main reason of the deviation was inadequate cover dimensions. In specimen SC_44_22_22_530_T6, number transverse reinforcement was increased to 6 stirrups to overcome the small cover and spacing problem. However, increased number of stirrups inside a small side and face cover caused weak plane and measured bar stress decreased.

Gegenstand der Arbeit ist die Entwicklung eines numerischen Stoffgesetzes, welches die materialspezifischen Besonderheiten Selbstverdichtender Betone in jungem Alter erfasst. Durch das erhöhte Schwindmaß eines Selbstverdichtenden Betons innerhalb der ersten zwölf Stunden können Dehnungszustände hervorgerufen werden, welche zu Schädigungen führen, die von den einschlägigen Normen bisher noch nicht erfasst wurden. Im Zuge des Forschungsprojektes „Selbstverdichtender Beton im Untertagebau“ konnten Erkenntnisse über das materialspezifische Verhalten bei konstanten Umgebungsbedingungen erlangt werden. Diese Ergebnisse wurden mit übertägig gewonnen Daten verglichen, um eine klare Abgrenzung zu einem normalen Rüttelbeton zu ziehen. Im weiteren Verlauf wurden die Ergebnisse zur Kalibrierung einer numerischen Simulation herangezogen. Damit kann nun, in Abhängigkeit der relativen Luftfeuchtigkeit und der Bauteilgröße, das Dehnungsverhalten eines SVB in jungem Alter realitätsnah beschrieben werden.

Fresh properties of mortars are important factors in altering the performance of self compacting concrete (SCC). Measurement of the rheological properties of the fine mortar part of concrete is generally used in the mix design of SCC. It can be stated that SCC rheology can be optimized if the fine mortar part of concrete is designed properly. However, measurement of the rheological properties is often impractical due to the need for complex equipment. Therefore, more practical methods of assessing mortar workability are often preferred. In this study, four mineral admixtures, three superplasticizers (SP) and two viscosity modifying admixtures (VMA) were used to prepare self compacting mortar (SCM). The mineral admixtures included fly-ash, brick powder, limestone powder, and kaolinite. Two of the SPs were polycarboxylate based and another one was melamine formaldehyde based. One of the viscosity modifying admixtures was based on an aqueous dispersion of microscopic silica and the other one was based on high molecular weight hydroxylated polymer. Within the scope of the experimental program, 43 mixes of SCM were prepared from different materials with keeping the amount of mixing water constant. Workability of the fresh mortar were determined using V - funnel and slump flow tests. The setting time of the mortars, were also determined. The hardened properties that were determined included the ultrasonic pulse velocity (UPV) and the strength which was determined at 7, 28, and 56 days. It was concluded that among the mineral admixtures used, only fly-ash and limestone powder increased the workability of the mixes. The two polycarboxylate based SPs yield approximately the same workability and the melamine formaldehyde based SP was not as effective as the other two.

Made available in DSpace on 2014-06-11T19:27:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-26Bitstream added on 2014-06-13T20:16:15Z : No. of bitstreams: 1 santos_lf_me_ilha.pdf: 6137370 bytes, checksum: 5de758f11cce6406d87fe87638a96bb5 (MD5) / O concreto auto-adensável (CAA) é um material que representa um dos maiores avanços na tecnologia do concreto das últimas décadas. O desenvolvimento do CAA propiciou eficiência e melhora nas condições de trabalho em canteiro de obras e na indústria de pré-moldados. Do ponto de vista reológico, o CAA é uma mistura fluida que proporciona diferenças de comportamento quando comparado ao concreto convencional. Neste contexto, a proposta desta pesquisa foi estudar, num primeiro plano, as características reológicas nas fases de pasta, argamassa e concreto do CAA no estado fresco e seu comportamento no estado endurecido. Para isso, optouse por empregar a metodologia de Repette e Melo (2005), que considera a resistência à compressão como ponto de partida para a composição do traço do CAA e que estuda os aspectos reológicos envolvidos nas diferentes fases de sua dosagem. Os materiais empregados para estudo de dosagem foram o fíler basáltico como adição, areia média, brita 19 mm, aditivo superplastificante e dois tipos de cimento. Foram elaborados dois concretos, com cimentos distintos, ambos com mesma classe de resistência igual a 40 MPa. Num segundo plano, foi realizado um estudo da avaliação da resistência à compressão desses concretos quando submetidos à cura térmica a vapor, variando-se as temperaturas de cura (entre 65oC e 80oC), assim como o patamar isotérmico de cura em 4 h,6 h e 8 h para cada temperatura. A avaliação das propriedades mecânicas dos concretos foi realizada empregando o Método da Maturidade. No emprego da maturidade foram utilizados as funções de Nurse e Saul e a proposta por Freiesleben-Hansen e Pedersen (FHP). As análises comparativas foram realizadas em função do tipo de cimento empregado, temperatura de cura e tempo de patamar isotérmico / The self-compacting concrete (SCC) is a material that represents one of the greatest advances in concrete technology in recent decades. The development of SCC has resulted in improved efficiency and working conditions at the construction site and the precast industry. Rheological point of view, the SCC is a fluid mix that provides behavior differences when compared to conventional concrete. In this context, the proposal of this research was to study, in the foreground, the rheological phases of paste, mortar and concrete of SCC in the fresh state and its behavior in the hardened state. For this, we chose to employ the methodology Repette e Melo (2005), which considers the compressive strength as a starting point for the composition of the trace of SCC and studying the rheological aspects involved in the different stages of their dosage. The materials used to study the dosage was basalt fillers such as addition, medium sand, gravel 19 mm, superplasticizer additive and two types of cement. We prepared two concretes with different cements, both with the same strength class of 40 MPa. In the background, a study assessing the compressive strength of concrete when subjected to steam curing, varying the curing temperatures (between 65oC and 80oC) as well as the level of isothermal cure at 4 h, 6 h and 8 h for each temperature. The evaluation of mechanical properties of concrete was carried out using the Maturity Method. Employment of maturity was used to Nurse e Saul function, as well as function proposed by Freiesleben-Hansen and Pedersen (FHP). Comparative analysis were performed according to the type of cement used, curing temperature and isothermal plateau

Orientador: Maria da Consolação Fonseca de Albuquerque / Resumo: O trabalho apresenta um estudo exploratório sobre o uso de cinzas de casca de arroz como finos em argamassas autoadensáveis. Para tanto foram realizadas composições de argamassas vibradas e autoadensáveis variando-se os parâmetros tais como a relação água/cimento, superplastificante/cimento, e volume de agregado miúdo/volume de argamassa, mantendo-se constante a relação finos/cimento, e as relações água/materiais secos, bastante próximas. Foram realizados ensaios no estado fresco e no estado endurecido. Para o estado fresco foram realizados de modo a poder nortear as composições, a saber: ensaio Flow- table para os casos de argamassas vibradas e de espalhamento Slump-flow para os casos de argamassas autoadensáveis, ensaio Slump-test para os casos de argamassas vibradas e de escoamento confinado V-funnel para os casos de argamassas autoadensáveis, e avaliação da massa específica aparente. No estado endurecido foram realizados os ensaios de resistência à compressão simples e diametral, e os de absorção d’água. Os resultados foram então comparados uns com os outros ou analisados dentro do seu contexto. Encontraram-se valores que puderam corroborar para as vantagens do uso das cinzas de casca de arroz nas argamassas autoadensáveis, sobretudo nos resultados relativos aos valores das resistências mecânicas alcançadas e dos níveis de absorção d’água. Observou-se também aparente rigidez para os casos das argamassas autoadensáveis. Observou-se que as argamassas autoadensáveis podem al... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The paper presents an exploratory study on the use of rice husk ash as fine in self-compacting mortars. Therefore, we conducted compositions vibrated and self-compacting mortars varying parameters such as the water/cement superplasticizer/cement ratio and the volume of fine aggregate/volume of mortar, keeping constant the fines/cement ratio, and the relationship water/dry materials very close. Assays were performed in fresh and hardened state. For fresh state were conducted in order to guide the compositions as follows: Flow-test table for cases of vibrated mortar Slump-flow and spread in cases of self-compacting mortar, Slump-test assay for the cases of mortars vibrated and V-funnel flow confined to cases self-compacting mortars, and evaluation of the bulk density. In the hardened state were performed strength tests to simple and diametrical compression, and the water absorption. The results were then compared with each other or analyzed in context. They met values that might corroborate the advantages of the use of rice husk ash in self-compacting mortars, particularly in the results for the values of mechanical strength and achieved the levels of water absorption. There was also apparent rigidity for cases of self-compacting mortars. It was observed that the mortar self-compacting can achieve a differentiated behavior in decreasing the water absorption values over time in order to anticipate these reductions within their maximum permitted levels. / Mestre

The self-compacting concrete (SCC) has been characterized as a great evolution in the concrete technology, being able to fill all empty spaces of the formwork and selfcompacting only by action of its own weight. If steel fibers are added to SCC, without prejudice its properties in the fresh state, new advantages and possibilities of applications will provide concretes more efficient. In this context, a SCC with addition of industrial waste is used, and steel fibers with l/d ratio equal to 50 are incorporated, in a volume fraction of 1%, in order to assess the behavior of reinforced self-compacting concrete beams, with and without the addition of steel fibers, subject to normal and tangential stresses, and compare them with the behavior of conventional reinforced concrete beams. For that, were made reinforced concrete beams of dimensions (12,5 x 23,5 x 132) cm, which were tested by four-point bending, to the 28 days of age. To compare the results, were produced conventional concretes of different compositions, with and without steel fibers. The tests results in the fresh state shown that was possible the obtaining of concrete with self-compacting properties, even with the addition of steel fibers, from a mix already existent of SCC. The addition of the steel fibers to the SCC promoted slight gain in the load capacity of the beam, with lower displacements in the middle span, lower deformations in the reinforcement bars and improved cracking control, compared to the others beams produced with concrete compacted by vibration, with and without steel fibers. / O concreto auto-adensável (CAA) vem se caracterizando como uma grande evolução na tecnologia do concreto, sendo capaz de preencher todos os espaços vazios da fôrma e adensar-se apenas pela ação de seu peso próprio. Se ao CAA adicionam-se fibras de aço, sem prejuízo de suas propriedades no estado fresco, novas vantagens e possibilidades de aplicação proporcionarão concretos mais eficientes. Dentro desse contexto, um CAA com adição de resíduo industrial é usado, e fibras de aço com relação l/d = 50 são incorporadas, em uma fração volumétrica de 1%, com intuito de avaliar o comportamento de vigas de concreto auto-adensável armado, com e sem o reforço de fibras de aço, submetidas às solicitações normais e tangenciais, e compará-las com o comportamento de vigas de concreto armado convencional. Para isso, foram confeccionadas vigas de concreto armado de dimensões (12,5 x 23,5 x 132) cm, as quais foram ensaiadas por flexão a quatro pontos, aos 28 dias de idade. Para comparação dos resultados, foram produzidos concretos convencionais de diferentes composições, com e sem a adição das fibras de aço. Os resultados dos ensaios no estado fresco mostraram que foi possível a obtenção de concreto com propriedades auto-adensáveis, mesmo com adição de fibras de aço, a partir de uma dosagem de CAA já existente. A adição das fibras de aço ao CAA promoveu sensível ganho na capacidade resistente da viga, com menores flechas, menores deformações das armaduras, longitudinal e transversal, e melhorado controle da fissuração, em comparação às demais vigas produzidas com concretos adensados por vibração, com e sem fibras de aço.

Submitted by ANNA BEATRIZ ALVES DE MELLO null (eng.annabeatriz@gmail.com) on 2016-09-26T17:26:57Z No. of bitstreams: 1 Argamassas autoadensáveis utilizando cinzas de casca de arroz como finos - comparação com o caso de argamassas vibradas.pdf: 4452313 bytes, checksum: 5912cb6b4a6d246206f745348ff2b0e1 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-09-27T17:47:58Z (GMT) No. of bitstreams: 1 mello_aba_me_ilha.pdf: 4452313 bytes, checksum: 5912cb6b4a6d246206f745348ff2b0e1 (MD5) / Made available in DSpace on 2016-09-27T17:47:58Z (GMT). No. of bitstreams: 1 mello_aba_me_ilha.pdf: 4452313 bytes, checksum: 5912cb6b4a6d246206f745348ff2b0e1 (MD5) Previous issue date: 2016-08-01 / O trabalho apresenta um estudo exploratório sobre o uso de cinzas de casca de arroz como finos em argamassas autoadensáveis. Para tanto foram realizadas composições de argamassas vibradas e autoadensáveis variando-se os parâmetros tais como a relação água/cimento, superplastificante/cimento, e volume de agregado miúdo/volume de argamassa, mantendo-se constante a relação finos/cimento, e as relações água/materiais secos, bastante próximas. Foram realizados ensaios no estado fresco e no estado endurecido. Para o estado fresco foram realizados de modo a poder nortear as composições, a saber: ensaio Flow- table para os casos de argamassas vibradas e de espalhamento Slump-flow para os casos de argamassas autoadensáveis, ensaio Slump-test para os casos de argamassas vibradas e de escoamento confinado V-funnel para os casos de argamassas autoadensáveis, e avaliação da massa específica aparente. No estado endurecido foram realizados os ensaios de resistência à compressão simples e diametral, e os de absorção d’água. Os resultados foram então comparados uns com os outros ou analisados dentro do seu contexto. Encontraram-se valores que puderam corroborar para as vantagens do uso das cinzas de casca de arroz nas argamassas autoadensáveis, sobretudo nos resultados relativos aos valores das resistências mecânicas alcançadas e dos níveis de absorção d’água. Observou-se também aparente rigidez para os casos das argamassas autoadensáveis. Observou-se que as argamassas autoadensáveis podem alcançar um comportamento diferenciado na diminuição dos valores de absorção d’água com o tempo, de modo a se antecipar estas reduções dentro de seus níveis máximos permitidos. / The paper presents an exploratory study on the use of rice husk ash as fine in self-compacting mortars. Therefore, we conducted compositions vibrated and self-compacting mortars varying parameters such as the water/cement superplasticizer/cement ratio and the volume of fine aggregate/volume of mortar, keeping constant the fines/cement ratio, and the relationship water/dry materials very close. Assays were performed in fresh and hardened state. For fresh state were conducted in order to guide the compositions as follows: Flow-test table for cases of vibrated mortar Slump-flow and spread in cases of self-compacting mortar, Slump-test assay for the cases of mortars vibrated and V-funnel flow confined to cases self-compacting mortars, and evaluation of the bulk density. In the hardened state were performed strength tests to simple and diametrical compression, and the water absorption. The results were then compared with each other or analyzed in context. They met values that might corroborate the advantages of the use of rice husk ash in self-compacting mortars, particularly in the results for the values of mechanical strength and achieved the levels of water absorption. There was also apparent rigidity for cases of self-compacting mortars. It was observed that the mortar self-compacting can achieve a differentiated behavior in decreasing the water absorption values over time in order to anticipate these reductions within their maximum permitted levels.

The objective of this paper is to present the results of the connection between a substrate and self-compacting concrete with underwater launch simulating the repairs to concrete structures submerged in various applications. Therefore, we used samples of "old" concrete structures extracted from the Power Plant Itumbiara the state of Goiás, which was considered substrates. The concrete used in this work follows the parameters established strengths in the research completed in 2003 by the laboratory of Furnas Centrais Elétricas and has been adjusted to the materials (gravel and sand) found in the city of the Minas Gerais. The results are from the sample concrete of vertical and horizontal joints of the bodyspecimens prismatic concrete substrates and kept submerged and extracted after a year, so almost complete hydration. The analysis relating to the launch of concrete indicate that it is entirely feasible production for small applications. Visibility during the concreting was hampered by increased turbidity of the water produced by the concrete, so you must reduce the presence of a direct flow of water in concrete. The analysis was by comparing the results of the testimonies and bodies-of-proof. We observed an increase in strength in direct relation to the diameter of the testimony. In the samples concrete of 50 mm x 100 mm was obtained a coefficient of variation of 9.00% giving the concrete a low variability. The testimonies of concrete compounds and submerged concrete substrate (with seal inclined) had a resistance value 84% over the bodies-of-proof. The tensile strength by diametrical compression of the testimony amounted to 54% of the reference value. Can also check the interface between substrate concrete and after the break. / O objetivo deste trabalho é apresentar os resultados do estudo da ligação entre um substrato e o concreto auto-adensável com lançamento subaquático simulando a realização de reparos em estruturas de concreto submersas em diversas aplicações. Para tanto foram utilizadas amostras de concreto antigo provenientes de estruturas extraídas da Usina Hidrelétrica de Itumbiara no estado de Goiás, que foram considerados substratos, o concreto utilizado no presente trabalho segue os parâmetros de dosagens estabelecidos na pesquisa concluída em 2003 pelo laboratório de Furnas Centrais Elétricas e foi ajustado aos materiais (brita e areia) encontrados na região de Uberlândia do Estado de Minas Gerais. Os resultados obtidos são provenientes de testemunhos das juntas verticais e horizontais dos corpos-de-prova prismáticos concretados com substratos e mantidos submersos e extraídos após um ano, portanto, a hidratação quase completa. As análises relativas ao processo de lançamento do concreto indicam que é totalmente viável sua produção para pequenas aplicações. A visibilidade durante a concretagem foi dificultada pelo aumento de turbidez da água produzida pelo concreto, portanto deve-se diminuir a presença de um fluxo de água direto no concreto. As análises foram por comparação entre os resultados dos testemunhos e dos corpos-de-prova. Foi observado um aumento da resistência em relação direta ao diâmetro do testemunho. Nos testemunhos de 50 mm x 100 mm obteve-se um coeficiente de variação de 9% dando ao concreto uma variabilidade baixa. Os testemunhos compostos de concreto submerso e substrato de concreto (com junta inclinada) obtiveram uma resistência com valor 84% em relação os corpos-de-prova. A resistência à tração por compressão diametral dos testemunhos correspondeu a 54% do valor de referência. Também pode ser verificada a interface entre substrato e concreto após a ruptura. / Mestre em Engenharia Civil