Maestría en Ingeniería Civil con Mención en Estructuras Metálicas

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    Análisis del comportamiento mecánico del acero estructural ASTM A36 r recubierto con materiales ignífugos luego que han sido sometidos a altas temperaturas.
    (Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas., 2025) Núñez Acosta Ivonne Alexandra; Guamanquispe Toasa Patricio
    In Ecuador, ASTM A36 steel is widely used in metal structures due to its strength and ductility, although it loses mechanical properties at elevated temperatures, such as during fire exposure. While intumescent coatings are employed as passive protection, there is limited local research on their effectiveness on this type of steel, representing a critical gap in structural safety. This study followed ISO 12944 and E119-24 standards to define the requirements for thermal testing. An experimental methodology was developed, preceded by documentary and patent research to identify fireproof coatings available in the country. Three different formulations were applied to ASTM A36 steel specimens, which were then subjected to temperatures of 600 °C, 800 °C, and 1000 °C for intervals of 3, 4, and 5 minutes. Metallographic, hardness, and tensile tests were conducted, and results were compared to a control sample with no coating or thermal exposure. The bestperforming coating underwent further testing at extended exposure times of 30, 45, and 60 minutes. The results indicate that the most representative formulations belong to DEKORUM INQUIFESA, with the X-50 coating standing out. This formulation exhibited minimal variation in carbon content (0.26–0.29%), low Brinell hardness loss (minimum 139.5 HB), and yield strength variations ranging only from 1% to 9%. In fire simulation tests, X-50 outperformed uncoated steel, showing up to 69% improvement in tensile strength. However, after 30 minutes of continuous hightemperature exposure, the coating’s effectiveness decreased, suggesting the need for complementary active protection systems to prevent structural failure.