Coupled reliability model of biodeterioration, chloride ingress and cracking for reinforced concrete structures

International audienceMaintaining and operating civil infrastructure systems has been recognized as a critical issue worldwide. Among all possible causes of safety reduction during the structural lifetime, deteriora- tion is particularly important. Structural deterioration is usually a slow time-dependent process controlled by safety and operation threshold specifications. This paper presents a model of RC deterioration by coupling biodeterioration (i.e., chemical, physical and mechanical action of live organisms), steel corrosion, and concrete cracking. The final purpose of the model is to compute the reduction of the concrete section and the area of steel reinforcement in order to assess the change of structural capacity with time. Given the uncertainties in both the parameters and the model, the probabilistic nature of loads, the material properties and the difussion process are taken into account to evaluate structural reliability. The model is illustrated with an example where the inelastic behavior of a pile subject to random loading is considered. The results of the analysis have shown that the effect of biodeterioration on the structural performance is significant and can cause an important reduction of its lifetime. On the whole, the paper states that modeling the effects of biodeterioration in RC structures should be included as part of infrastructure planning and design, especially, when they are located in aggressive environments

National Theatre, historical monument of Brasília : case study

Este trabajo es parte de un Acuerdo de Cooperación Internacional para la conservación de monumentos históricos de hormigón armado en Brasilia. Esta investigación es el resultado de una inspección rutinaria en el Teatro Nacional de Brasilia, ciudad reconocida por la UNESCO, en 1987, como patrimonio cultural de la humanidad. La estructura, toda en hormigón armado, fue concebida por el arquitecto Osear Niemeyer, con un total de 48 m de altura y 42.000 m2 de área construida. Tras investigar la documentación disponible, se procedió a la identificación y al estudio de los daños existentes. El hormigón presenta un buen estado de conservación, salvo en algunas regiones de la estructura: estructura armada expuesta, oxidación de la estructura armada, infiltración, moho y eflorescencia son algunos de los daños que se encontraron. __________________________________________________________________________________________________________ ABSTRACTThis work is part o f an International Cooperation Agreement fo r the conservation o f historical monuments made o f reinforced concrete in Brasilia. This research is based on a routine inspection o f the National Theatre o f Brasilia, a city recognized by UNESCO in 1987 as world cultural heritage. The structure, entirely made o f reinforced concrete, was conceived by architect Oscar Niemeyer, and has a total o f 48 m o f height and 42,000 m2 o f constructed area. After examining the available documentation, the existing damage was then identified and mapped. The concrete shows a good state o f conservation, with the exception o f some regions o f the structure: the damages found were exposed armature, oxidation o f armature, infiltration, mold and efflorescence

Etude de la microstructure du beton sous l'influence de variations hygrometriques importantes

Available at INIST (FR), Document Supply Service, under shelf-number : 22859, issue : a. 1991 n.10 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Etude de la microstructure du beton sous influence de variations hygrometriques importantes

SIGLEINIST T 74666 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Etude de la microstructure du beton sous influence de variations hygrometriques importantes

SIGLEINIST T 74666 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc