Techniques of performance-based design in fire safety have developed notably in the past two decades. One of the reasons for departing from the prescriptive methods is the ability of performance-based methods to form a scientific basis for the cost-risk-benefit analysis of different fire safety alternatives. Apart from few exceptions, observation of past fires has shown that the structure’s contribution to the overall fire resistance was considerably underestimated. The purpose of this research is to outline a risk-based design approach for structures in fire. Probabilistic methods are employed to ascertain uniform reliability indices in line with the classical trend in code development. Modern design codes for complex phenomena such as fire have been structured to facilitate design computations. Prescriptive design methods specify fire protection methods for structural systems based on laboratory controlled and highly restrictive testing regimes. Those methods inherently assume that the tested elements behave similarly in real structures irrespective of their loading, location or boundary conditions. This approach is contested by many researchers, and analyses following fire incidents indicated alarming discrepancy between anticipated and actual structural behaviour during real fires. In formulating design and construction codes, code writers deal with the inherent uncertainties by setting a ceiling to the potential risk of failure. The latter process is implemented by specifying safety parameters, that are derived via probabilistic techniques aimed at harmonising the risks ensuing different load scenarios. The code structure addresses the probability of failure with adequate detail and accuracy. The other component of the risk metric, namely the consequence of failure, is a subjective field that assumes a multitude of variables depending on the context of the problem. In codified structural design, the severity of failure is implicitly embodied in the different magnitudes of safety indices applied to different modes of structural response. This project introduces a risk-based method for the design of structures in fire. It provides a coherent approach to a quantified treatment of risk elements that meets the demands of performance-based fire safety methods. A number of proposals are made for rational acceptable risk and reliability parameters in addition to a damage index with applications in structural fire safety design. Although the example application of the proposed damage index is a structure subjected to fire effects, the same rationale can be easily applied to the assessment of structural damage due to other effects.

As estruturas de concreto, especialmente as pontes de concreto, estão sujeitas a um conjunto de ações que leva ao seu envelhecimento devido aos processos de deterioração, muitas vezes deixando de responder às exigências para as quais foram projetadas. Tal situação, em muitos casos, é agravada pela falta de conhecimento dos processos e mecanismos de degradação assim como o uso de técnicas tradicionais para inspeção de estruturas, estas muitas vezes se mostram limitadas quando são aplicadas isoladamente. Este trabalho mostra uma comparação entre a inspeção visual (usada há décadas) e a aplicação de métodos de ensaios não destrutivos e semi-destrutivos na avaliação da condição estrutural atual de pontes. Enquanto a inspeção visual mostra uma condição qualitativa, os métodos de ensaios não destrutivos são quantitativos e apresentam o potencial de determinar os danos no interior da estrutura que não são visíveis a olho nu. Portanto, visando alertar para o problema da degradação das pontes, busca-se integrar a inspeção visual com a avaliação através do uso de métodos de ensaio. Assim, neste trabalho é feito um estudo de caso da ponte sobre o rio Jaguari. Este estudo visa determinar a condição atual da estrutura através de ensaios não destrutivos e semi-destrutivos, estabelecendo uma correlação entre os resultados destes ensaios e a avaliação da inspeção visual. Dessa forma, procura-se apresentar uma alternativa na avaliação de pontes de concreto. / Concrete structures, particularly concrete bridges, are subjected to a set of actions that leads to aging due to the processes of deterioration, and many times these structures do not respond to the demands for which they have been designed. This situation, in many cases, is exacerbated by lack of knowledge of processes and mechanisms of degradation and by the use of traditional techniques for inspection of structures, these techniques are limited when applied alone. This work shows a comparison between the visual inspection (used for decades) and the application of nondestructive testing methods and semi-destructive on the evaluation of current structural condition of bridges. While visual inspection shows a qualitative condition, the methods of nondestructive testing are quantitative and have the potential to determine the damage inside the structure that are not visible with a simple view. Therefore, in order to draw attention to the problem of deterioration of bridges, we seek to integrate the visual inspection with the assessment through the use of test methods. Thus, in this work a case study of the bridge about the river Jaguari is done. This study aims at determining the current condition of the structure through nondestructive and semi-destructive methods, establishing a correlation between the results of these tests and the evaluation of visual inspection. We seek to present an alternative in the assessment of concrete bridges.

As estruturas de concreto, especialmente as pontes de concreto, estão sujeitas a um conjunto de ações que leva ao seu envelhecimento devido aos processos de deterioração, muitas vezes deixando de responder às exigências para as quais foram projetadas. Tal situação, em muitos casos, é agravada pela falta de conhecimento dos processos e mecanismos de degradação assim como o uso de técnicas tradicionais para inspeção de estruturas, estas muitas vezes se mostram limitadas quando são aplicadas isoladamente. Este trabalho mostra uma comparação entre a inspeção visual (usada há décadas) e a aplicação de métodos de ensaios não destrutivos e semi-destrutivos na avaliação da condição estrutural atual de pontes. Enquanto a inspeção visual mostra uma condição qualitativa, os métodos de ensaios não destrutivos são quantitativos e apresentam o potencial de determinar os danos no interior da estrutura que não são visíveis a olho nu. Portanto, visando alertar para o problema da degradação das pontes, busca-se integrar a inspeção visual com a avaliação através do uso de métodos de ensaio. Assim, neste trabalho é feito um estudo de caso da ponte sobre o rio Jaguari. Este estudo visa determinar a condição atual da estrutura através de ensaios não destrutivos e semi-destrutivos, estabelecendo uma correlação entre os resultados destes ensaios e a avaliação da inspeção visual. Dessa forma, procura-se apresentar uma alternativa na avaliação de pontes de concreto. / Concrete structures, particularly concrete bridges, are subjected to a set of actions that leads to aging due to the processes of deterioration, and many times these structures do not respond to the demands for which they have been designed. This situation, in many cases, is exacerbated by lack of knowledge of processes and mechanisms of degradation and by the use of traditional techniques for inspection of structures, these techniques are limited when applied alone. This work shows a comparison between the visual inspection (used for decades) and the application of nondestructive testing methods and semi-destructive on the evaluation of current structural condition of bridges. While visual inspection shows a qualitative condition, the methods of nondestructive testing are quantitative and have the potential to determine the damage inside the structure that are not visible with a simple view. Therefore, in order to draw attention to the problem of deterioration of bridges, we seek to integrate the visual inspection with the assessment through the use of test methods. Thus, in this work a case study of the bridge about the river Jaguari is done. This study aims at determining the current condition of the structure through nondestructive and semi-destructive methods, establishing a correlation between the results of these tests and the evaluation of visual inspection. We seek to present an alternative in the assessment of concrete bridges.