Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-14T22:33:05Z No. of bitstreams: 1 ThiagoVieiraFonseca_DISSERT.pdf: 2958142 bytes, checksum: c66f334f99f3044869ebf39752984389 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-16T19:54:31Z (GMT) No. of bitstreams: 1 ThiagoVieiraFonseca_DISSERT.pdf: 2958142 bytes, checksum: c66f334f99f3044869ebf39752984389 (MD5) / Made available in DSpace on 2017-03-16T19:54:31Z (GMT). No. of bitstreams: 1 ThiagoVieiraFonseca_DISSERT.pdf: 2958142 bytes, checksum: c66f334f99f3044869ebf39752984389 (MD5) Previous issue date: 2016-12-15 / O concreto autoadens?vel (CAA) possui elevado teor de materiais finos e vem sendo bastante utilizado devido as suas caracter?sticas de alta fluidez e coes?o. Os finos provindos de res?duos ou subprodutos industriais podem vir a ser usados em prol da sustentabilidade, minimizando consideravelmente o consumo de cimento associado ? possibilidade de manter, ou melhorar, as propriedades mec?nicas ou de durabilidade. Desta forma, o presente trabalho investigou a viabilidade do desenvolvimento de CAA?s confeccionados com elevados teores de adi??es minerais e cal hidratada. Para isso, o cimento foi substitu?do por adi??es minerais (pozolana da casca do arroz, metacaulim e f?ler calc?rio) no teor de 60%, com base no tra?o de refer?ncia com consumo de 451,1 kg/m? de cimento, originando novos tra?os com consumos de cimento entre 167,7 kg/m? e 173,3 kg/m?. A cal hidratada foi incorporada como adi??o em tr?s tra?os no teor de 5% sobre a massa total dos materiais finos. Os CAA?s foram caracterizados no estado fresco pelos ensaios de espalhamento, T500, anel-J, funil-V e caixa-L. Para avalia??o do desempenho mec?nico dos CAA?s foram realizados ensaios de resist?ncia ? compress?o, velocidade do pulso ultrass?nico e m?dulo de elasticidade est?tico, bem como propriedades de transporte relacionadas ? durabilidade: absor??o por capilaridade, difus?o de ?ons cloreto, resistividade el?trica e carbonata??o. Os CAA?s com adi??es minerais apresentaram desempenho mec?nico satisfat?rio, embora inferiores ao do tra?o de refer?ncia. As resist?ncias ? compress?o aos 28 dias dos concretos com adi??es minerais apresentaram redu??o de 15 a 60% em rela??o ao tra?o de refer?ncia, mas todos os resultados foram compat?veis com concretos estruturais de acordo com os requisitos da NBR 6118 (ABNT, 2014). Com rela??o a durabilidade, os concretos com adi??es minerais apresentaram redu??o do coeficiente de difus?o de ?ons cloreto que variaram entre 25,4% e 74,8%. As resistividades el?tricas do concreto de refer?ncia foram bastante inferiores ?s dos concretos com adi??es minerais, mas todas as composi??es estudadas foram classificadas como prov?vel taxa de corros?o desprez?vel. As resistividades el?tricas sofreram grande redu??o quando analisadas em amostras carbonatadas. J? a an?lise da carbonata??o acelerada mostrou que a substitui??o do cimento por adi??es minerais em elevados teores torna os CAA?s bastante suscet?veis a carbonata??o. Quanto a adi??o de cal hidratada, n?o foi verificada influ?ncia positiva no desempenho mec?nico dos CAA?s estudados, mas observou-se que sua utiliza??o proporcionou redu??o da profundidade de carbonata??o nos CAA?s devido a reposi??o da reserva alcalina. / Self-compacting concrete (SCC) has a high content of fine materials and has been widely used due to its characteristics of high fluidity and cohesion. Fines from industrial waste or by-products may be used for the sake of sustainability, considerably reducing the consumption of cement associated with the possibility of maintaining or improving mechanical or durability properties. In this way, the present work investigated the feasibility of the development of SCC's made with high levels of mineral additions and hydrated lime. For this purpose, the cement was replaced by mineral additives (rice husk pozzolan, metakaolin and limestone filer) in the 60% content, based on the reference mixture with consumption of 451.1 kg / m? of cement, giving rise to new mixtures with consumption of cement between 167.7 kg / m? and 173.3 kg / m?. The hydrated lime was incorporated as an addition in three mixtures in the content of 5% on the total mass of the fine materials. The SCC's were characterized in the fresh state by the slump flow test, T500, J-ring, V-funnel and L-box. To evaluate the mechanical performance of the SCC's, tests of compressive strength, ultrasonic pulse velocity and static modulus of elasticity, as well as transport properties related to durability were performed: capillary absorption, chloride ion diffusion, electrical resistivity and carbonation. The SCC's with mineral additions presented satisfactory mechanical performance, although lower than the reference mixture. The compressive strength at 28 days of the concretes with mineral additions showed a reduction of 15 to 60% in relation to the reference mixture, but all the results were compatible with structural concretes according to the requirements of NBR 6118 (ABNT, 2014). Regarding the durability, the concrete with mineral additions presented reduction of the diffusion coefficient of chloride ions that varied between 25.4% and 74.8%. The electrical resistivities of the reference concrete were much lower than those of the concretes with mineral additions, but all the studied compositions were classified as probable negligible corrosion rates. The electrical resistivities suffered great reduction when analyzed in carbonated samples. The analysis of the accelerated carbonation showed that the substitution of cement by mineral additions at high levels makes the SCC very susceptible to carbonation. As for the addition of hydrated lime, there was no positive influence on the mechanical performance of the SCC's studied, but it was observed that its use provided a reduction of the carbonation depth in the SCC's due to the alkaline reserve.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T23:06:42Z No. of bitstreams: 1 WesleyFeuDosSantos_DISSERT.pdf: 2488767 bytes, checksum: 54fa9201753bfbbe0b0ff0a295b2a4ac (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-24T21:53:11Z (GMT) No. of bitstreams: 1 WesleyFeuDosSantos_DISSERT.pdf: 2488767 bytes, checksum: 54fa9201753bfbbe0b0ff0a295b2a4ac (MD5) / Made available in DSpace on 2017-03-24T21:53:11Z (GMT). No. of bitstreams: 1 WesleyFeuDosSantos_DISSERT.pdf: 2488767 bytes, checksum: 54fa9201753bfbbe0b0ff0a295b2a4ac (MD5) Previous issue date: 2016-09-09 / A fabrica??o do Cimento Portland ? uma atividade que causa grande impacto ambiental devido ? sua elevada taxa de emiss?o de CO2 na atmosfera. Visando reduzir esse impacto, a viabilidade t?cnica de materiais alternativos em substitui??o ao Cimento Portland tem sido cada vez mais analisada. J? s?o conhecidos os benef?cios que as adi??es minerais infere ao concreto convencional (CV), no entanto, existe a necessidade de compreender melhor seus benef?cios quando utilizadas em CAA e verificar o comportamento deste quando curado termicamente. Assim, este trabalho avalia os efeitos da incorpora??o de f?ler calc?rio (Fc) e metacaulim (Mk) na hidrata??o do concreto autoadens?vel, quando submetido ? cura t?rmica. Para tanto, foram produzidos seis composi??es de CAA, sendo uma de refer?ncia, sem adi??o mineral, quatro misturas bin?rias com substitui??o do cimento por 10% de Mk, 10% Fc, 20% de Mk e 20% Fc e uma terci?ria com substitui??o do cimento por 10% de Mk e 10% de Fc. Os concretos foram dosados e realizados os ensaios realizados para os concretos dosados foram: slump flow, T500, L-box, V-test e J-ring para caracteriza??o do CAA no estado fresco. Ap?s iniciada a pega (aproximadamente 3 horas), intervalo chamado de pr?-cura, os corpos de prova moldados foram curados atrav?s de imers?o total em banho aquecido. A taxa de aquecimento utilizada foi de 20 ?C/h, chegando ?s temperaturas m?ximas de 50, 60 e 70 ?C, com posterior resfriamento de 10 ?C/h. O tempo total do ciclo (pr?-cura, aquecimento, patamar isot?rmico e resfriamento), foi de 18 a 20 horas. Tamb?m foram confeccionados corpos de prova de CAA que foram curados por imers?o em ?gua a temperatura ambiente. As propriedades analisadas no estado endurecido de todas as composi??es foram: resist?ncia ? compress?o nas idades de 1, 3, 7 e 28 dias, com m?dulo de elasticidade din?mico, absor??o de ?gua por capilaridade, massa espec?fica e absor??o total aos 28 dias de idade. A an?lise da microestrutura dos diferentes concretos se deu por microscopia eletr?nica de varredura e difra??o de raios X aos 3 e 28 dias de idade. As adi??es de metacaulim e filer calc?rio podem substituir o cimento Portland, nos percentuais de 10% e 20%, de maneira satisfat?ria em misturas bin?rias e terci?rias. Aos 28 dias de idade, os CAA curados termicamente em geral n?o apresentaram resist?ncias ? compress?o inferiores aos curados a 28 ?C. A cura t?rmica ?mida por imers?o propicia um aumento na resist?ncia ? compress?o nas primeiras idades, exceto para os concretos contendo 20% de f?ler calc?rio em substitui??o ao cimento Portland. Para cada tra?o estudado, houve um temperatura que se mostrou mais eficaz, ou seja, uma temperatura patamar mais adequada. Na an?lise da microestrutura dos CAA pode se observar que a elevada resist?ncia obtida a 1 dia de idade, deve-se a r?pida forma??o de CSH para os CAA tratados termicamente. / The manufacture of Portland cement is an activity that causes great environmental impact due to its high CO2 emission rate in the atmosphere. In order to reduce this impact, technical feasibility of alternative materials to replace Portland cement has been increasingly analyzed. It is already known the benefits that mineral additions infers to conventional concrete (CV), however, little is known of their use in self-compacting concrete (SCC) subjected to heat treatment. This work evaluates the effects of the incorporation of limestone fillers (LP) and metakaolin (MK) in the hydration of self-compacting concrete, when subjected to thermal curing. For this purpose six SCC compositions were produced, as a reference without mineral addition, four binary mixtures with replacement of cement with 10% MK, 10% LP, 20% MK and 20% LP and a tertiary with substitution of cement by 10% MK and 10% LP. The concrete were measured and made the tests slump flow, T500, L-box, V-test and J-ring to characterize the SCC fresh. After started the crystallization reactions (about 3 hours), range called pre-curing, the molded specimens were cured through total immersion in a warm bath. The heating rate used was 20 ?C/hr, reaching the maximum temperatures 50, 60 and 70 ?C, with subsequent cooling 10 ?C/hr. The total cycle time (pre-curing, heating, cooling and isothermal level) was 18 to 20 hours. Also, specimens were prepared which were cured by immersion in water at room temperature. The analyzed properties in the hardened state of all compositions were compressive strength at ages of 1, 3, 7 and 28 days at modulus, water absorption by capillarity, density, and total absorption to 28 days of age. The analysis of the microstructure of different concrete was given by scanning electron microscopy and X-ray diffraction at 1 and 28 days of age. The CAA thermally cured obtained a high increase in compressive strength at 1 day old, when compared to CAA cured at room temperature. For each dosage analyzed, there is a maximum temperature within the thermal cycle, which provides better mechanical performance to the CAA. The thermal curing causes changes in the microstructure, including, promote the rapid formation of calcium silicate hydrate (CSH). The additions of metakaolin and lime filer can replace Portland cement in percentages of 10% and 20%, satisfactorily in binary and tertiary mixtures. After 28 days the CAA cured thermally groups showed no resistance to compression to lower cured at 28 ? C. The wet thermal curing dip provides an increase in compressive strength at early ages, except for the concrete containing 20% filler limestone to replace Portland cement. For each studied trait, there was a temperature that was more effective, i.e., a temperature most suitable level. The analysis of the microstructure of the CAA can be seen that the high strength obtained at 1 day old, due to rapid formation of the CSH to the heat-treated CAA.

Submitted by Jadson Francisco de Jesus SILVA (jadson@uefs.br) on 2018-01-30T22:07:52Z No. of bitstreams: 1 Uiliana M?rcia da Silva Merc?s Farias_2017.pdf: 5844655 bytes, checksum: 1df6b86cb5dfd9f89a7bbd299fa1bf93 (MD5) / Made available in DSpace on 2018-01-30T22:07:52Z (GMT). No. of bitstreams: 1 Uiliana M?rcia da Silva Merc?s Farias_2017.pdf: 5844655 bytes, checksum: 1df6b86cb5dfd9f89a7bbd299fa1bf93 (MD5) Previous issue date: 2017-03-20 / The use of waste from Dimension Stone Industry as an inert material can be a good way to promote the sustainability of the construction sector. The Cariri stone is one of the dimension stones explored in state of Ceara, in Brazil. Thus, this work was developed with the main goal of studying a self-compacting concrete production (SCC) using Cariri stone sawdust waste (CSSW) in partial replacement with the natural fine aggregate. The SCC was designed using the method proposed by Melo (2005) considering two w/c ratios (0.57-0.70), and 10% of CSSW. The study was carried out in three stages: material characterization, mortar phase evaluation and SCC phase evaluation. In the fresh state, SCC was evaluated for fluidity, plastic viscosity, blocking capacity and segregation resistance, using V funnel, J-Ring, L-box and segregation column. In the hardened state, the SCC was evaluated for axial compressive strength, splitting tensile strength and water absorption, void index and specific density. The results showed that CSSW improve SCC cohesiveness and homogeneity, and it is feasible to apply up to 10% of CSSW in SCC production. / No sentido de promover a sustentabilidade do setor da constru??o civil, procura-se alternativas para diminuir o impacto ambiental gerado, atrav?s da descoberta de novos materiais alternativos, como os res?duos da ind?stria de beneficiamento de rochas ornamentais. Dentre os tipos de rochas ornamentais exploradas no Brasil, destaca-se um calc?rio laminado conhecido como ?Pedra Cariri?, que ? explorado no estado do Cear?. Assim, esse trabalho foi desenvolvido com o objetivo de estudar a produ??o de concreto autoadens?vel (CAA) utilizando res?duos de serragem de pedra Cariri (RSPC) em substitui??o parcial ao agregado mi?do natural. Utilizando a metodologia de Melo (2005) para produ??o de CAA, foram definidas as rela??es a/c (0,57-0,70). O estudo se deu em tr?s etapas: caracteriza??o dos materiais, fase argamassa e fase CAA. No estado fresco, o CAA foi avaliado quanto ? fluidez, viscosidade pl?stica, habilidade passante e resist?ncia ? segrega??o, por meio do ensaio de espalhamento, funil V, Anel J, Caixa L e coluna de segrega??o. No estado endurecido, o CAA foi avaliado quanto ? resist?ncia ? compress?o axial, ? resist?ncia ? tra??o por compress?o diametral e ? absor??o de ?gua, ?ndice de vazios e massa espec?fica. Os resultados indicaram a possibilidade da aplica??o de at? 10% de RSPC na produ??o de CAA.

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.