Resistência à compressão de concretos microfissurados: influência da incorporação de vidro cominuído e do tipo de cura

Abstract

The use of glass in the formation of cement-based materials can be not only economic advantageous, but also environmentally friendly, as it reduces the use of new natural materials. This paper aims to evaluate the mechanical behavior and the phenomenon of self-healing of structural concretes produced with crushed glass as a fine aggregate, subjected to early loading at early ages and cured in different curing processes. For the production of concrete, CP V ARI cement and a trace were used to guarantee the characteristic of structural concrete. Glass was used in substitution by mass of 20% in relation to the fine aggregate. After casting, the concretes received initial submerged curing until the age of seven days, when they were removed from curing. Subsequently, a portion of the samples were subjected to a compression load of 75% of its resistant capacity, whereas the other samples remained intact. This methodology intended to create a significant internal damage in the cement matrix for later evaluation of the self-healing of the concrete. Afterwards, the specimens were divided into two groups and redirected to continue curing in different processes (dry curing in a controlled environment and submerged curing). The mechanical property of axial compressive strength was evaluated at day 28, resulting in all the specimens’ strengths above 39 MPa, which indicates that the preloading applied in part of the concretes in the early ages did not impair their final mechanical performance. The results also showed that the compressive strength of the specimens in dry cure was higher. In conclusion, the incorporation of glass in the 20% content promoted a reduction in the axial compressive strength, although the pozzolanity of the glass was not observed in this analysis. Keywords: Glass sand. Self-healing. Cure. Compressive strength.