Effect of fibre morphology on flocculation of fibre-cement suspensions

Autor(es)

Tonoli, G. H. D. ^[1] ; Fuente, E. ^[2] ; Monte, C. ^[2] ; Savastano, Jr., H. ^[3] ; Rocco Lahr, F. A. ^[1] ; Blanco, A. ^[2]

Afiliação do(s) autor(es)

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

^[2] Univ Complutense Madrid, Dept Chem Engn, F CC Quim, E-28040 Madrid - Spain

^[3] Univ Sao Paulo, Dept Food Engn, Fac Anim Sci & Food Engn, BR-13635900 Pirassununga, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CEMENT AND CONCRETE RESEARCH; v. 39, n. 11, p. 1017-1022, NOV 2009.
• Citações Web of Science: 25

Resumo

The objective of the present research was to evaluate the effect of fibre morphology (e.g., length, width, fibrillation, broken ends, content of fines and number of fibres per gram) on flocculation and drainage properties of fibre-cement suspensions and on physical properties of the fibre-cement composites. Mechanical refining was used to change the morphological properties of Eucalyptus and Pinus pulps. Results show that the mechanical refining increased the size of the formed flocs and decreased the concentration of free small particles (with dimensions between 1 and 20 pm) as a consequence of the increased fibrillation and content of fines, which increased the capacity of the fibres to capture the mineral particles. High levels of refining were necessary for Pinus pulp to obtain cement retention values similar to those obtained by unrefined Eucalyptus pulp. This is due to the higher number of fibres per gram in Eucalyptus pulp than in Pinus pulp. Pulp refining improved the packing of the particles and, although decreased the drainage rate. it contributed to a less porous structure, which improved the microstructure of the composite. (C) 2009 Elsevier Ltd. All rights reserved. (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