Concrete structures, durability, carbonation, reliability index, Eurocodes

conference paper

English

The failure criteria of Serviceability Limit States are linked to design service life. Moreover, different levels of reliability should be adopted for different types of Limit States. The choice of level of reliability for a particular structure and material should take account of the relevant factors, including possible consequences of failure and potential costs of safety measures. This principle is not fully accommodated in current codes. In the context of durability of reinforced concrete structures, the European codes EN 206 and EN1992-1 together with EN1990 provide recommendations for different exposition and structural classes as to the minimum content of cement, maximum water/cement ratio, and, optionally, minimum concrete strength class. Limiting concrete cover is required simultaneously. The relevance of these requirements and associated values of the index of reliability is more than obvious. By utilizing analytical models for carbonation progress in concrete and taking account of the uncertainties of concrete mixture, carbon dioxide concentration and other input data, a statistical description of carbonation progress is gained. Random or deterministic input parameters are involved. Statistical analysis is performed allowing for calculation of the reliability index relevant to different service lifes. The time passing before the initiation of rebar corrosion is considered as the limiting condition. The results of the investigation of the reliability index profiles and its trends concerning different conditions/classes are provided utilizing an interactive web-site covering service life, concrete cover and reliability index assessment. The non-uniformity of reliability level is shown. Some conclusions (and generated questions) are discussed.

Concrete structures, durability, carbonation, reliability index, Eurocodes

TEPLÝ, B.; ROVNANÍK, P.; KERŠNER, Z.; CHROMÁ, M.

2005

17. 4. 2005

Lyon

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