Fuzzy Time-Dependent Reliability Analysis of RC Beams Subject to Pitting Corrosion

Steel bars pitting corrosion is an electrochemical process that could seriously jeopardize the reliability of reinforced concrete structures. Even if detailed models exist to predict the lifetime of the concrete element when it is subject to this environmental attack, their applications present serious limitations that undergo, to the noteworthy sources of, uncertainty of many problem parameters. This restriction could produce erroneous solutions, especially when analysis deals with existing buildings or little information about problem parameters are accessible. In detail this takes place when real environmental conditions, mechanical properties as well as load conditions, could only be estimated and not known with enough accuracy. To overcome this problem, some methodologies have been developed, assuming that uncertainty variables can be suitably modeled in a probabilistic way, and therefore traditional theories for reliability assessment can be used. Nonetheless, in the analysis of this problem, there are other parameters that cannot be treated opportunely in a probabilistic way. The main purpose of this paper is to develop an efficient alternative approach for time-dependent reliability analysis regarding reinforced concrete beams subject to pitting corrosion, when probabilistic and nonprobabilistic parameters occur at the same time. With this new approach, it is possible to obtain a versatile tool to support the decision maker in planning maintenance interventions.