Evaluation of concrete structures duralibility under risk of carbonation
Lech Edward Czarnecki , Piotr Paweł Woyciechowski
AbstractAuthors The mechanism of reinforced concrete structures degradation under the risk of carbonation and chloride corrosion and its relation to the life cycle of the structure are shown. The models of carbonation progress and chloride migration in concrete are analyzed. Preferences of hyperbolic model of carbonation and the special role of its asymptote as the limit defining the depth of carbonation have been shown. Conditions for the initiation of corrosion in concrete elements with particular attention to the critical chloride concentration are defined. Various methods of determining the distribution profile of chlorides in concrete with particular emphasis on the diffusion coefficient of chloride are discussed. Four possible procedures of determining apparent diffusion coefficient are shown. The first is a computational method based on theoretical equation of chloride distribution in concrete space between surface and maximal depth of measurements. The second one is based on the determination of chloride distribution model using “best fitting curve” method. The third one is estimative—graphical way of determining of diffusion coefficient and the fourth is the calculation of the expression erfc(b) from the equation of diffusion, on the basis of experimentally measured values of chloride concentration, and then, by using the tabularized values of erfc—determining the value of its argument (in parenthesis) and finally the value D0. Examples of using this procedures and threat of possible errors and mistakes are shown also. On this basis an algorithm for predicting the durability of concrete structures under conditions of potential corrosion has been elaborated. The examples of the use of this algorithm are shown.
|Publication size in sheets||0.3|
|Book||Dehn F. et al (eds.): Concrete Repair, Rehabilitation and Retrofitting IV.+ CD, 2016, Taylor & Francis Group, ISBN 978-1-138-02843-2, [978-1-315-67754-4], 246 p.|
|Score|| = 15.0, 19-06-2017, BookChapterMatConf|
= 15.0, 19-06-2017, BookChapterMatConf
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