Analysis of mechanical and microstructural properties of high performance concretes containing nanosilica and silica fume

Materia

article

Jéssica Zamboni Schiavon¹  Pietra Moraes Borges¹  Sérgio Roberto da Silva¹  Jairo José de Oliveira Andrade¹ 

[1] Programa de Pós-Graduação em Engenharia e Tecnologia de Materiais

关键词: high performance concrete;    Light curing;    silica fume;    nanosilica;    mechanical properties;    microstructure;   

DOI  :  10.1590/S1517-707620210004.1304

学科分类：工程和技术（综合）

来源: Universidade Federal do Rio de Janeiro * Coordenacao dos Programas de Pos-Graduacao de Engenharia

【 摘 要 】

The use of nanomaterials in concrete has shown promise, and the use of several types in cementitious compounds has been found to guarantee greater physical–mechanical properties and improvements in microstructure. The use of mineral admixtures, such as silica fume, ensures the improvement of the interfacial transition zone (ITZ) between aggregate and paste in high-performance concrete (HPC). Thus, this work evaluates the performance of superplasticizer additive with colloidal nanosilica suspension and slurried silica fume with HPC and its macro- and micro-structural properties. The mechanical (i.e., compressive strength and elastic modulus) and microstructural properties via (scanning electron microscopy and X-ray micro tomography) of concretes with 1.5 and 3% nanosilica and 5 and 10% silica fume included in the evaluation methods in this study. The results indicate that, with the use of mineral admixtures, the compressive strength and elastic modulus of concrete increased significantly. The concrete with the use of 10% silica fume and 3% nanosilica resulted in a showed an increased strength over 75% at 28 days. Besides that, for same w/b = 0.35 the elastic modulus increased by 36% compared with the reference concrete. The microstructural investigations show that the nanosilica and silica fume led to a densification of microstructure, which is responsible for the improvement of HPC performance.

【 授权许可】

CC BY