Effect of colloidal silica on the mechanical properties of fiber-cement reinforced with cellulosic fibers

Author(s)

Santos, Sergio Francisco ^[1] ; Rodrigues, Jose de Anchieta ^[2] ; Denzin Tonoli, Gustavo Henrique ^[3] ; Feuzicana de Souza Almeida, Alessandra Etuko ^[4] ; Savastano, Jr., Holmer ^[4]

Affiliation

^[1] State Univ Sao Paulo, Dept Mat & Technol, BR-12516410 Guaratingueta, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Mat Engn, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Fed Lavras, Dept Forest Sci, BR-37200000 Lavras, MG - Brazil

^[4] Univ Sao Paulo, Dept Biosyst Engn, BR-13635900 Pirassununga, SP - Brazil

• Document type: Journal article
• Source: Journal of Materials Science; v. 49, n. 21, p. 7497-7506, NOV 2014.
• Web of Science Citations: 12

Abstract

The effect of colloidal silica on the hydration reaction of the Portland cement system and its effect on the resulting mechanical properties are not completely understood. Silica nanoparticles can affect the behavior and performance of fiber-cement, such as the calcium-silicate-hydrate gel of the matrix and the fiber-matrix interface bonding. The main objective of this study is to evaluate the effects of various contents of colloidal silica (0, 1.5, 3, 5, and 10 % w/w) on the microstructure and mechanical performance of cement composites reinforced with cellulosic pulp. Fiber-cement composites with unbleached eucalyptus Kraft pulp as the micro-fiber reinforcement were produced by the slurry dewatering technique followed by pressing. The average values of the modulus of rupture of the fiber-cement decreased with increasing colloidal silica content. However, the pullout of the fibers increased significantly in the fiber-cement composites with additions between 3 and 10 % w/w of colloidal silica suspension, as indicated in the scanning electron microscopy images and by the improvement in the energy of fracture values. (AU)

• FAPESP's process: 08/04769-9 - Degradation study of cellulosic fibers in cementitious composites: contribution to sustainable constructive materials
• Grantee: Alessandra Etuko Feuzicana de Souza Almeida
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 09/10614-0 - Fundamental mechanical characteristics of non-conventional composites reinforced with cellulose and synthetic fibres: contribution to sustainable building materials
• Grantee: Holmer Savastano Junior
• Support Opportunities: Regular Research Grants
• FAPESP's process: 09/17293-5 - Fracture mechanics applied to the development of non conventional extruded composites reinforced with cellulosic and synthetic fibers
• Grantee: Sérgio Francisco dos Santos
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 10/16524-0 - Fracture mechanics applied to the development of non conventional extruded composites reinforced with cellulosic and syntetic fibers
• Grantee: Sérgio Francisco dos Santos
• Support Opportunities: Scholarships in Brazil - Young Researchers