Abstract
Abstract
Aged concrete structures, such as those in hydroelectric plants, suffer from degradation of the cementitious matrix due to environmental factors, leading to reduced durability and increased maintenance costs. This study evaluates the efficacy of a novel repair product, Elera, composed of colloidal nanosilica dispersed in potassium silicate, acrylic latex (Acronal BS 700), water, and fumed nanosilica, for recovering the calcium silicate hydrate (C-S-H) matrix in aged concrete samples from hydraulic tubes in the Assis Chateaubriand Hydroelectric Plant (UHE Mimoso). Thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) were performed at heating rates of 10°C/min and 20°C/min to assess diffusion-induced penetration and matrix recovery. Results indicate successful diffusion and C-S-H recovery in highly porous aged hydraulic tube samples, with increased mass percentage in the 450–520°C range, attributed to pozzolanic reactions. However, in lower-porosity UHE samples, penetration was limited, suggesting the need for alternative transport mechanisms like injection. The presence of acrylic latex was confirmed, and the study highlights the potential for self-healing concrete applications. This research advances sustainable repair strategies for critical infrastructure.