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Abstract(s)
As estruturas em betão armado apresentam um bom comportamento durante e após incêndio podendo na generalidade ser reparadas. Para avaliar a reparabilidade destas, é apresentada uma metodologia que fornece as ferramentas para determinar se é possível e/ou vantajoso proceder à sua reparação.
São abordados os métodos de modelação de incêndio e como avaliar o seu impacto em elementos de betão armado segundo a EN 1991-1-2 e EN 1992-1-2 respetivamente.
É também apresentada a metodologia de avaliação, tipos de dano causados pelo incêndio, propriedades residuais dos materiais, um sistema de classificação de danos e uma abordagem geral aos métodos de reparação.
Uma estimativa para a severidade de um incêndio é apresentada com recurso a uma curva paramétrica além de um estudo da evolução da resistência residual de um pilar, viga e laje sujeitas á curva incêndio padrão. Neste estudo são também comparados os fatores de redução para as caraterísticas mecânicas apresentados pela EN 1992-1-2 e os obtidos por via experimental. É também apresentado como determinar a resistência residual de uma viga com a profundidade de isotérmica já conhecida.
Conclui-se que a consideração das propriedades do local onde ocorreu o incêndio é importante para uma boa estimativa da severidade de um incêndio e que a temperatura máxima atingida pela armadura é o fator determinante para a resistência residual de vigas e lajes.
Concrete structures have shown good performance both during and after a fire, with repairs usually possible. To evaluate their reparability, a methodology is presented which gives the tools to determine if it’s possible and/or advantageous to proceed with repairs. Methods to model a fire and evaluate its impact in concrete structures according to EN 1991-1-2 and EN 1992-1-2 respectively are addressed. The methodology of evaluation, types of damage caused by fire, residual properties of materials, a damage classification system and a general approach to repair methods are also presented. An estimate for the severity of a fire is presented using a parametric curve in addition to the study of the evolution of the residual resistance of a beam, pillar and slab subject to the standard fire curve. In this study the reduction factors for the mechanical characteristics presented by EN 1992-1-2 and those obtained through testing are also compared. It is also presented how to determine the residual strength of a beam with a known isothermal depth. It is concluded that the consideration of the local properties where the fire occurred is important for a good estimate of the severity of a fire and that the maximum temperature reached by the reinforcement is the determining factor for the residual resistance of beams and slabs.
Concrete structures have shown good performance both during and after a fire, with repairs usually possible. To evaluate their reparability, a methodology is presented which gives the tools to determine if it’s possible and/or advantageous to proceed with repairs. Methods to model a fire and evaluate its impact in concrete structures according to EN 1991-1-2 and EN 1992-1-2 respectively are addressed. The methodology of evaluation, types of damage caused by fire, residual properties of materials, a damage classification system and a general approach to repair methods are also presented. An estimate for the severity of a fire is presented using a parametric curve in addition to the study of the evolution of the residual resistance of a beam, pillar and slab subject to the standard fire curve. In this study the reduction factors for the mechanical characteristics presented by EN 1992-1-2 and those obtained through testing are also compared. It is also presented how to determine the residual strength of a beam with a known isothermal depth. It is concluded that the consideration of the local properties where the fire occurred is important for a good estimate of the severity of a fire and that the maximum temperature reached by the reinforcement is the determining factor for the residual resistance of beams and slabs.
Description
Keywords
Incêndio Betão Resistência residual Avaliação Reparabilidade Fire Concrete Residual strength Assessment Reparability