Durability of Concrete After Fire Through Accelerated Carbonation Tests

Abstract

Degradation of mechanical properties and durability of reinforced concrete structures occur when they are subjected to fire situations, depending on the characteristics of the material, fire duration and the ways of fire extinguishing. Mechanical properties such as compressive strength, tensile strength and elasticity modulus are some examples of typically altered characteristics in concrete during high temperature exposure. Nevertheless, little is known about the advance of the carbonation front on fire-damaged concrete, which is a characteristic directly related to the durability of the structural system. For this purpose, the carbonation front was evaluated in specimens with characteristic strengths of 20 MPa and 35 MPa, subjected to high temperatures (200 °C, 500 ºC and 700 ºC) and different types of cooling (fast and slow). It was observed that the concrete durability is harmed by exposure to high temperatures and fast cooling. However, advance of the carbonation front was not verified in slow cooling situations.

Efectos Del Fuego Sobre La Resistencia De Elementos Estructurales De Hormigón Armado: Una Revision De Literatura

“…Cuando una estructura de hormigón armado sufre un incendio, su rendimiento mecánico y durabilidad se verán reducidas, en función de las características del material, la duración del incendio y la forma de extinguirlo. Las propiedades mecánicas que cambian durante la exposición a altas temperaturas son: resistencia a la compresión, tracción y el módulo de elasticidad (de Assis Oliveira et al, 2019).…”

Geotechnical Behavior of Soil-electric Arc Furnace Slag Mixtures Under Carbonation

“…CO 2 saturation in the chamber environment is performed manually by daily interleaved ows until a CO 2 concentration of 100% is reached. This method of CO 2 application has also been used by other authors [72][73][74]. The temperature in the environment of the accelerated carbonation chamber was between 20 and 25ºC.…”

Influência da temperatura no comportamento mecânico de uma viga de concreto armado

“…Teixeira (2018) avaliou a interferência da resistência inicial, do nível de temperatura atingido e do tipo de resfriamento na resistência e no módulo de elasticidade do concreto pósincêndio e concluiu que quanto menor a resistência inicial maior é a perda de rigidez e, além disso, que resfriamentos bruscos resultam em maior redução nas propriedades mecânicas residuais. Oliveira et al (2019) avaliaram o avanço da frente de carbonatação -característica diretamente relacionada à durabilidade do sistema estrutural -no concreto danificado pelo fogo e verificaram a influência do tipo de resfriamento neste fenômeno. Daware et al (2022) apresentaram os resultados de ensaios experimentais realizados em blocos de alvenaria de concreto para investigar a degradação induzida pelo fogo.…”