Análise do comportamento mecânico do concreto submetido à altas temperaturas.

Abstract

Concrete is a material formed by the mixture of cement, gravel, water, coarse and fine aggregates. It holds tremendous importance in the construction industry, making ongoing research and improvements essential. One crucial area of study is the influence of high temperatures on the mechanical strength of concrete, considering that a structure is always susceptible to failures, and some of these failures can lead to fires, causing material losses and even loss of human life. The objective of this work is to conduct a study to evaluate the level of influence that high temperatures have on concrete, specifically in terms of mechanical properties related to tensile and compressive strength. The considered temperatures were: ambient temperature (27°C), 150°C, 300°C, 450°C, 600°C, and 750°C. Test specimens were prepared for compression and flexural tensile strength tests, resulting in six specimens for each temperature and test, amounting to a total of 6 specimens for each temperature and test. It was observed that the load-carrying capacity of the concrete decreases as the temperature increases. Up to a temperature of 450°C, the reduction in compressive and tensile strength is similar. However, at a temperature of 600°C, the reduction in compressive strength is 20% greater compared to the reduction in tensile strength. It was also possible to identify the appearance of fissures in the test specimens starting from a temperature of 600°C.