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Previous issue date: 2011-02-10 / The search for alternative materials with lower density, reduction in heat transfer and
propagation of noise associated with the ease of handling and application in concrete
structures, represents an enormous challenge in the formulation and knowledge of
the performance of self-compacting lightweight concrete, which has technology little
known nationally, and appears on the international scene as an innovative material
and alternative to conventional concrete. Based on these, this study set out to study
self-compacting lightweight concrete made with two distinct grades of expanded clay
associated with the addition of plasticizing/superplasticizers additives and mineral
additions of metakaolin and bagasse ash of sugar cane. There is also an object of
study, evaluation of pozzolanic activity of mineral admixtures and their influence on
the durability characteristics of concrete. The rheological, physical, mechanical and
microstructural analysis in this study served as basis in the classification of concretes
autoadens?veis, targeting the national technical requirements for their classification
in the category autoadens?vel and lightweight structural. The inclusion of mineral
admixtures (metakaolin and bagasse ash of sugar cane), partial replacement of
cement, pozzolanic activity and demonstrated maintenance of mechanical properties
through the filler effect, a reduction of up to 76% of the nitrogen gas permeability in
blend with 20% bagasse ash. All concretes had rheology (cohesion and consistency)
suitable for self-adensability as well as strength and density inherent structural
lightweight concrete without presenting phenomena of segregation and exudation / A busca por materiais alternativos de menor massa espec?fica, redu??o na
transfer?ncia de calor e propaga??o do barulho, associado ? facilidade de manuseio
e aplica??o em estruturas de concreto armado, representa grande desafio na
formula??o e conhecimento do desempenho de concretos estruturais leves
autoadens?veis, que tem tecnologia pouco difundida em n?vel nacional, e surge no
cen?rio internacional como um material inovador e alternativo ao concreto
convencional. Frente ao exposto, este trabalho se prop?s a estudar concretos
estruturais leves autoadens?veis elaborados com duas gradua??es distintas de
argila expandida associados ? inclus?o de aditivos plastificantes/superplastificantes
e adi??es minerais de metacaulim e cinza de biomassa de cana-de-a??car. Tem-se
ainda como objeto do estudo, a avalia??o da atividade pozol?nica das adi??es
minerais e sua influ?ncia nas caracter?sticas de durabilidade dos concretos. As
propriedades reol?gicas, f?sicas, mec?nicas e microestruturais, analisadas neste
estudo, serviram como fundamenta??o na qualifica??o dos concretos leves
autoadens?veis, visando ?s exig?ncias t?cnicas nacionais para sua classifica??o no
quesito autoadens?vel e estrutural leve. A inclus?o das adi??es minerais
(metacaulim e cinza de biomassa de cana-de-a??car), em substitui??o parcial do
cimento, demonstrou atividade pozol?nica e manuten??o das propriedades
mec?nicas atrav?s do efeito filler, apresentando redu??o de at? 76% da
permeabilidade a g?s nitrog?nio na mistura com 20% de cinza de biomassa. Todos
os concretos dosados apresentaram reologia (coes?o e consist?ncia) adequada
para autoadensabilidade, bem como resist?ncia e massa espec?fica inerentes aos
concretos estruturais leves, sem apresentar fen?menos de segrega??o e exsuda??o
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/15567 |
| Date | 10 February 2011 |
| Creators | Borja, Edilberto Vitorino de |
| Contributors | CPF:15724520800, http://lattes.cnpq.br/0022988322449627, Melo, Marcus Ant?nio de Freitas, CPF:04514998320, http://lattes.cnpq.br/5840621182000517, Anjos, Marcos Alyssandro Soares dos, CPF:02262184496, http://lattes.cnpq.br/3904325866154130, Santos, Maria Luiza Lopes de Oliveira, CPF:87658968404, http://lattes.cnpq.br/7052771233872451, Martinelli, Ant?nio Eduardo |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Engenharia Mec?nica, UFRN, BR, Tecnologia de Materiais; Projetos Mec?nicos; Termoci?ncias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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