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.