Surface properties of eucalyptus pulp fibres as reinforcement of cement-based composites

Autor(es)

Denzin Tonoli, Gustavo Henrique ^[1] ; Feuzicana de Souza Almeida, Alessandra Etuko ^[2] ; Pereira-da-Silva, Marcelo Assumpcao ^{[3, 4]} ; Bassa, Alexandre ^[5] ; Oyakawa, Danilo ^[5] ; Savastano, Jr., Holmer ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Escola Engn Sao Carlos, Dept Struct Engn, BR-13566590 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Dept Food Engn, Fac Zootecnia & Engn Alimentos, BR-13566590 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Inst Fis Sao Carlos, Dept Phys & Mat Sci, BR-13566590 Sao Paulo - Brazil

^[4] UNICEP, Ctr Univ Cent Paulista, Sao Paulo - Brazil

^[5] CDTC, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: HOLZFORSCHUNG; v. 64, n. 5, p. 595-601, AUG 2010.
• Citações Web of Science: 19

Resumo

The objective of the present work is to evaluate the effects of the surface properties of unrefined eucalyptus pulp fibres concerning their performance in cement-based composites. The influence of the fibre surface on the microstructure of fibre-cement composites was evaluated after accelerated ageing cycles, which simulate natural weathering. The surface of unbleached pulp is a thin layer that is rich in cellulose, lignin, hemicelluloses, and extractives. Such a layer acts as a physical and chemical barrier to the penetration of low molecular components of cement. The unbleached fibres are less hydrophilic than the bleached ones. Bleaching removes the amorphous lignin and extractives from the surface and renders it more permeable to liquids. Atomic force microscopy (AFM) helps in understanding the fibre-cement interface. Bleaching improved the fibre- cement interfacial bonding, whereas fibres in the unbleached pulp were less susceptible to the re-precipitation of cement hydration products into the fibre cavities (lumens). Therefore, unbleached fibres can improve the long-term performance of the fibre-cement composite owing to their delayed mineralization. (AU)

• Processo FAPESP: 05/59072-4 - Utilização de fibras curtas de eucalipto em fibrocimento sem amianto
• Beneficiário: Gustavo Henrique Denzin Tonoli
• Modalidade de apoio: Bolsas no Brasil - Doutorado