On the mechanical properties and crack pattern analysis of a strain-hardening cement-based composite reinforced by natural sisal fibers

• Autor(a) principal: Teixeira,Felipe Pinheiro
• Data de Publicação: 2022
• Outros Autores: Souza,Felipe Rodrigues de, Lima,Victor Nogueira, Silva,Flávio de Andrade, Garcia,Sergio Luis González
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Matéria (Rio de Janeiro. Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-70762022000400205
• topic: Cement composite; Natural fibers; Mechanical properties; Crack pattern analysis

ABSTRACT Besides the strength enhancement and strain improvement (strain-hardening behavior), the use of natural fibers as reinforcement in cement-based matrices can also be highlighted as an economical and eco-friendly alternative for the future of the construction industry. In the present work, cement-based composites reinforced by natural sisal fibers were produced and tested under direct tensile loading. The Portland cement was partially replaced by pozzolans (metakaolin – MK and fly ash – FA), aiming to produce a calcium hydroxide-free matrix to ensure the durability of the fibers. The natural sisal fibers were used in a 5% volume fraction (in mass), divided into three layers. The mechanical properties of composite plates were compared to other literature results and demonstrated to be compatible with recent research. The crack pattern was analyzed by Digital Image Correlation (DIC) for a better understanding of their failure mechanisms. The material presented a tensile strength increase after the first crack formation, marked by multiple cracking partners from this point. Finally, a comparison between direct (LVDTs) and indirect (DIC) methods of strain measurement was done and demonstrated minor results for the DIC, approximately 84% of those obtained from the LVDTs.