Avaliação de cais protendido com pós-tração considerando a durabilidade análise numérica

Abstract

Port and harbour structures made of reinforced concrete are commonly used in brazilian engineering. Due the environment in which they are located, these structures are subjected to the action of several aggressive agents that can deteriorate the concrete itself and its reinforcement over time. With the objective of improving the characteristics that can increase the performance of these structures, the present work shows the study of some measures aimed at extend the service life of concrete structures considering durability. For this purpose, a comparison between brazilian NBR 6118 code and international concrete standards such as CEB-FIP Model Code and Eurocode is carried out. Furthermore, the deleterious actions are studied, as well as some ways to mitigate its effects. These included the use of post-tensioned prestressed concreted, once this technique allows the structure to have none or at least a low ratio of tension, improving the crack control, which is an important entry route for aggressive agents. Bearing in mind the use of prestressed concrete, a quay structure for berthing operations is proposed, for which a structural analysis is developed with the help of CsiBridge, a software originally meant to perform analysis in bridge structures, but which use is justified in this once a berthing structure is subject to several types of loads that can affect any part of the structure, referring to a influence-line analysis. In this analysis, the non-linear data and the time-dependent characteristics of the materials are taking in account, as well the losses of the prestressed and the influence of the construction process. As a conclusion of this work, one can show that the use of post-tensioned prestressed concrete is technically viable and that the current recommendations of brazilian and international codes are satisfactory regarding concrete structures protections in marine environment, although some other actions can be taken as a supplementary protection to these structures, as many designers do in other countries. About the use of CsiBridge, this study shows that this software can be properly used in berthing structures analysis, although the consideration of non-linearity and time-dependent properties are in a way complexes and require great efforts of post-processing.