$$\newcommand{\bra}[1]{\left<#1\right|}\newcommand{\ket}[1]{\left|#1\right>}\newcommand{\bk}[2]{\left<#1\middle|#2\right>}\newcommand{\bke}[3]{\left<#1\middle|#2\middle|#3\right>}$$
INFORMAÇÕES SOBRE DIREITOS AUTORAIS


As obras disponibilizadas nesta Biblioteca Digital foram publicadas sob expressa autorização dos respectivos autores, em conformidade com a Lei 9610/98.

A consulta aos textos, permitida por seus respectivos autores, é livre, bem como a impressão de trechos ou de um exemplar completo exclusivamente para uso próprio. Não são permitidas a impressão e a reprodução de obras completas com qualquer outra finalidade que não o uso próprio de quem imprime.

A reprodução de pequenos trechos, na forma de citações em trabalhos de terceiros que não o próprio autor do texto consultado,é permitida, na medida justificada para a compreeensão da citação e mediante a informação, junto à citação, do nome do autor do texto original, bem como da fonte da pesquisa.

A violação de direitos autorais é passível de sanções civis e penais.
Coleção Digital

Avançada


Estatísticas | Formato DC|



Título: EFFECTS OF RICE HUSK ASH ON PROPERTIES OF BAMBOO-PULP-REINFORCED CEMENT COMPOSITES
Instituição: PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO - PUC-RIO
Autor(es): CONRADO DE SOUZA RODRIGUES

Colaborador(es):  KHOSROW GHAVAMI - Orientador
Número do Conteúdo: 5002
Catalogação:  14/06/2004 Idioma(s):  PORTUGUESE - BRAZIL

Tipo:  TEXT Subtipo:  THESIS
Natureza:  SCHOLARLY PUBLICATION
Nota:  Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio.
Referência [pt]:  https://www.maxwell.vrac.puc-rio.br/colecao.php?strSecao=resultado&nrSeq=5002@1
Referência [en]:  https://www.maxwell.vrac.puc-rio.br/colecao.php?strSecao=resultado&nrSeq=5002@2
Referência DOI:  https://doi.org/10.17771/PUCRio.acad.5002

Resumo:
Asbestos is regarded as a hazardous material since the 60 s, motivating the efforts for the replacement of these mineral fibres in the vast range of materials in which they are applied as a raw material. Asbestos-cement was the first building material produced in large scale applying natural fibres as reinforcement in cement-based materials. Due the physical and mechanical behaviour and chemical stability of asbestos fibres, as well as their natural affinity with the cementitious matrix, asbestos-cement presents remarkable strength and durability, associated to a relative low cost. Such characteristics make the search for a suitable replacement to asbestos in fibre-cements a challenge, mobilizing industry and researchers since the early 70 s. Considering their availability and mechanical strength, cellulose fibres have proven to be a viable alternative to asbestos, being employed by the industry as reinforcement in fibre-cements for more than two decades. However, in spite of their well established production and commercialization in many parts of the world, some aspects of the cellulose-cement composites behaviour still motivates research efforts, which are mainly focused on durability aspects. The main deterioration mechanisms acting in cellulose-cement composites are all related to fluid transport within the pore network of the composites and the most applied treatment method is the partial replacement of cement by finely ground admixtures with high active silica content. The improvements in the durability aspects of composites are achieved by modifying the characteristics of the matrix and, mainly, the interfacial region. Rice husk is an agricultural residue produced in large scale in Brazil. If not applied as fuel in the rice mills or in others rural activities, the rice husk is disposed without control, resulting in an ecological problem. However, the pyrolysis of rice husk yields ash with high silica content, (80-90 percent). When burned in a proper way, this silica remains amorphous, presenting high reactivity with cement. Due to these characteristics rice husk ash, RHA, is applied in this PUC-Rio - Certificação Digital No 9924941/CA research as the treatment method in cement composites reinforced by bamboo pulp. It was observed that blended cement with up to 30 percent RHA with low carbon content resulted in a significant decrease in the porosity of the matrix and interface of the composite. As a consequence, these blended-cement composites presented water permeability expressively lower than that of the composites produced without RHA. High carbon content RHA was also applied, simulating the use of ash obtained by a non-controlled burning process. Similar results as those observed in composites with low-carbon-content RHA were achieved, once accelerated autoclave curing was applied to the composites. In this case, for better composite properties, higher RHA content must be used, with the best results being observed in composites with 50 percent RHA. Also, besides these aspects closely related to the main deterioration mechanisms of the composites, it was observed that RHA enhances the fiber-matrix interaction in the interface, improving the mechanical behaviour of the composites.

Descrição Arquivo
COVER, ACKNOWLEDGEMENTS, RESUMO, ABSTRACT, SUMMARY AND LISTS  PDF
CHAPTER 1  PDF
CHAPTER 2  PDF
CHAPTER 3  PDF
CHAPTER 4  PDF
CHAPTER 5  PDF
CHAPTER 6  PDF
CHAPTER 7  PDF
REFERENCES AND APPENDICES  PDF
Agora você pode usar seu login do SAU no Maxwell!!
Fechar Janela



* Esqueceu a senha:
Senha SAU, clique aqui
Senha Maxwell, clique aqui