Influência da cura térmica em geopolímeros à base de metacaulim

Abstract

Geopolymers are an alternative that has been proving interesting compared to the use of Portland cement due to the potential reduction of greenhouse gas emissions in the production of the material. However, its physical and mechanical characteristics still need to be further studied and disseminated in the literature. In this sense, the present work sought to evaluate the compressive strength of paste and metakaolin-based geopolymeric mortar subjected to different exposure times and thermal curing temperatures. For this, 7 experimental plans for the paste and 7 experimental plans for the mortar were elaborated, in which the curing temperature and the time of exposure to this temperature were varied and subsequently broken under compression to determine the average strength. There was a trend, in general terms, of resistance reduction as a function of temperature increase, a factor consistent with the results described in the literature. Furthermore, for paste, the best result was obtained for specimens cured at 40°C for 2h, with 28.06 MPa and for mortar, the best performance was for specimens cured at 60°C for 2h. It was concluded, therefore, that the curing temperature directly influenced the resistance of the paste and mortar specimens and the exposure time to this temperature influenced the resistance only of the mortar.