Estudo teórico do comportamento do concreto exposto a altas temperatura : uma revisão bibliográfica

Abstract

Concrete is widely used in civil construction due to its strength, durability, and non-combustible properties. However, when exposed to high temperatures, such as in fires or industrial environments near furnaces, concrete undergoes chemical, physical, and mechanical changes that can compromise the integrity of its properties. This theoretical study aims to present a literature review on the behavior of concrete subjected to extreme heat conditions, identifying the main damages that occur in its physical and chemical structure, altering its mechanical properties. Furthermore, exposure to high temperatures directly impacts the mechanical properties of concrete, such as compressive strength, tensile strength, and modulus of elasticity. Under intense heat scenarios, these properties can be severely compromised, resulting in loss of stiffness and load-bearing capacity, which affects the stability and safety of structures. The research also highlights the importance of concrete composition, emphasizing how the choice of aggregates and cement can influence the material's behavior when exposed to high temperatures. Components such as the type of aggregate, the water/cement ratio, and the thermal expansion coefficient are critical factors for the thermal resistance of concrete. To diagnose and assess heat-induced damage, various analysis methods were reviewed, including techniques that identify changes in the microstructure and macrostructure of concrete. These assessments are essential for understanding the thermal effects on the material and for proposing strategies to mitigate damage and restore structural integrity. Understanding the impacts of high temperatures on concrete is fundamental for developing more resilient and safer compositions, enabling the construction of buildings with greater durability. This study, therefore, contributes to the formulation of guidelines aimed at improving the thermal resistance of concrete, particularly in critical scenarios where structural safety is paramount.