Influência do uso de silano e nanossílica na resistência à compressão do concreto

Abstract

This study aims to evaluate the influence of silane and nanosilica in the compressive strength of the concrete by treating the aggregate surface or adding it in the water, both prior the concrete mixture. The additions and treatments with nanosilica and silane aim to improve the transition zone of the concrete by improving the chemical bonds between concrete phases and the densification of the transition zone. For that, an experimental study was carried out with five concretes, one of reference for comparative basis and four types of treatment: aggregate doped with nanosilica,aggregate doped with silane, nanosilica in water and silane in water. For the treatments and additions, nanosilica and silane were used in the colloidal state (2% od total water’s mass). For the evaluation of the properties the concretes were evaluated in the fresh state through the abatement, specific mass and incorporated air. In the hardened state they were evaluated by the compressive strength and scanning electron microscopy. The results showed that silane and nanosilica additions, such as treatment of the aggregate surface and addition in water, reduced the incorporated air, increased the consistency, but did not change the compressive strength of the concrete at 28 days, possibly due to the low amount used.