Análise da influência da nanosílica na resistência à compressão de concretos: uma revisão

Abstract

Currently, concrete is the most used material in civil construction for the most diverse types of constructions. Due to its importance for the area, more researches study about the physical and mechanical properties of the material and seek to improve them. Lately, the use of mineral additions in concretes has intensified in order to improve these characteristics. Among these improvements sought, there is greater durability of the structures. Thus, concomitant with the advancement of nanotechnology use in several areas, the addition of nanosilica in concrete seeks to provide a gain in the compressive strength and durability of the material. The present work had the intention to evaluate the effect of adding nanosilica to concrete, gathering data from scientific works and developing a database, which collected information such as nanosilica percentage and compressive strength values of cementitious materials. Firstly, 39 works were selected, 30 studies on concrete, 6 on cementitious paste and 3 on mortar, due to the higher number, it was chosen to continue with the analysis only for those which worked with concrete. Because of the heterogeneity between the samples and the large number of different nanosilica percentage observed, 24 in total, it was decided to restrict the analysis to 1%, 1.5%, 2%, 3% and 5% of addition of nanosilica for the ages of 7 and 28 days, since they had a larger number of samples. Graphical analyzes were performed using bar graphs, box-plot and linear regression, and Analysis of Variance - ANOVA, Tukey's Test and Anderson-Darling Test for Normality were also used to perform statistical analyses, comparing the values of the compressive strength of the nanosilica traces with the reference. From the results, the conclusion was that there is no significant difference in the compressive strength value of concretes with nanosilica compared to those without addition. However, this result could have been influenced due to the variability of characteristics between samples in the water/binder ratio for instance.