Título: | INFLUENCE OF SURFACE MODIFICATIONS ON SISAL FIBER DURABILITY AND INTERFACE BOND TOWARDS CEMENT-BASED MATRICES | ||||||||||||
Autor: |
RAYLANE DE SOUZA CASTOLDI |
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Colaborador(es): |
FLAVIO DE ANDRADE SILVA - Orientador LOURDES MARIA SILVA DE SOUZA - Coorientador |
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Catalogação: | 21/MAR/2023 | Língua(s): | ENGLISH - UNITED STATES |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||
Notas: |
[pt] 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. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=62036&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=62036&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.62036 | ||||||||||||
Resumo: | |||||||||||||
The use of sisal fiber in cementitious composites is a subject of current
relevance, mostly as a result of the growing interest to make the construction
industry more sustainable. However, there are also some drawbacks related to the
use of sisal fibers as reinforcement, such as the low durability in alkaline matrices.
Thus, this study aimed to investigate the changes in physical and mechanical
characteristics of sisal fiber through fiber modifications, to guarantee improved
performance as reinforcement in cement-based materials. Specifically, three
different fiber modifications have been considered: the alkaline treatment, the use
of a polymeric coating on the fiber surface, and a new technique of fiber surface
functionalization based on polyphenol chemistry. The experimental program
explored the modifications on treated fibers in terms of water absorption tendency,
microstructural changes, fiber composition, tensile strength, and strain capacity.
Additionally, a fundamental understanding of the interfacial properties between the
fiber surface and the cementitious matrix was assessed. The investigations also
included creep tests to evaluate the long-term performance of sisal fibers in
aggressive conditions, considering different levels of sustained loads. It has been
proven that all the proposed fiber modifications lead to improved physical,
mechanical, durability-related, and time-dependent properties of sisal fibers, as well
as enhancing fiber-matrix adhesion. Nonetheless, in terms of physico-mechanical
performance and durability, the best results were reached by the polyphenol
modified sisal fiber. After exposure to aggressive alkaline solution under loading,
natural sisal remained only with 38 percent of its strength capacity, changing to
approximately 55 percent for the modified fibers. The outcome of this study provided
technical information to consolidate the use of sisal fibers as a reliable alternative
to synthetic fibers for achieving structural cementitious composites.
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