Compressive strength analysis of conventional concrete subjected to high temperatures

Abstract

Concrete is one of the most used materials in civil construction, and its behavior in the face of high  temperatures has become an issue of interest in recent years, since the occurrence of fires is difficult to predict, compromising the structure of the affected buildings and consequently, security. Concrete  performs well in situations with high temperatures, because in addition to its resistance, it has low  thermal conductivity, is not combustible and does not emit toxic gases. However, when exposed to fire,  it undergoes physical, chemical and mechanical changes, capable of compromising its structural  functionality. In order to analyze the compressive strength of concrete after suffering the effects of high  temperatures with direct action of flames, tests were carried out on specimens submitted to fire at  different times, simulating a real fire situation. The results showed that, after 2 hours of exposure to  fire, the concrete loses 79.25% of its initial resistance. It was also observed that the longer the exposure  time and the increase in temperature, the greater the loss of resistance to compression, reaching a loss  of 85.20% with 12 hours of exposure.