Mechanical properties and microstructure of high performance concrete containing stabilized nano-silica

ABSTRACT Nanotechnology can significantly improve the mechanical strength and durability of concrete. At the nanoscale, good dispersion of constituent materials is an essential factor for the improvement of concrete properties. In this scenario, the objective of this research was to evaluate the mec...

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Detalles Bibliográficos
Autores: Abreu,Gustavo Braz de, Costa,Suéllen Mota Marques, Gumieri,Adriana Guerra, Calixto,José Márcio Fonseca, França,Fabrício Carlos, Silva,Cláudio, Quinõnes,Alberto Delgado
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:Brasil
Institución:Matéria (Rio de Janeiro. Online)
Repositorio:Matéria (Rio de Janeiro. Online)
Idioma:inglés
OAI Identifier:oai:scielo:S1517-70762017000200403
Acceso en línea:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-70762017000200403
Access Level:acceso abierto
Palabra clave:Nano-silica
high performance concrete
compressive strength
secant modulus of elasticity
microstructure
Descripción
Sumario:ABSTRACT Nanotechnology can significantly improve the mechanical strength and durability of concrete. At the nanoscale, good dispersion of constituent materials is an essential factor for the improvement of concrete properties. In this scenario, the objective of this research was to evaluate the mechanical properties of high performance concrete containing stabilized nano-silica. The incorporation of nano-silica to the polycarboxylate chemical admixture allowed its application in concrete, since the nano-silica was evenly dispersed in the concrete mass. For this study, three different concretes were employed: a reference concrete, one containing stabilized nano-silica and another containing a mixture of silica fume and stabilized nano-silica. The evaluated concrete mechanical properties were the axial compressive strength and secant modulus of elasticity measured in three different ages. The results indicated a substantial increase in concrete compressive strength and modulus of elasticity with the addition of stabilized nano-silica combined with a reduction in cement content. The results also showed that use of stabilized nano-silica proved to be very advantageous, especially when mixed with silica fume. When they were combined, a synergy effect occurred in the concrete that was of chemical nature in addition to the physical effect of better concrete particle packaging. Analysis by scanning electron microscopy showed the improvement in microstructure of concretes with stabilized nano-silica, which contributed to gains in mechanical properties.