Time dependent reliability analysis of corrosion induced concrete cracking

Determining corrosion-induced concrete cracking is essential to predicting the serviceability of corrosion-affected reinforced concrete structures and to instigating maintenance and repairs for the structures. This paper attempts to present a reliability-based methodology for serviceability assessment of corrosion-affected concrete structures, using the performance criterion of concrete crack width. A stochastic model for crack width is developed and a time-dependent method is employed to quantify the probability of serviceability failure so that the time for the structure to be unserviceable and, hence, requiring repairs, can be determined with confidence. A parametric study is also undertaken to identify the factors that affect the failure due to corrosion-induced concrete cracking. A merit of the proposed methodology is that the structural assessment is directly related to one of the design criteria used by practitioners. It is found that corrosion-induced concrete cracking can be modeled as a stochastic process with little autocorrelation and that the corrosion rate is the most important single factor that affects cracking failure. The methodology presented herein can serve as a tool for structural engineers and asset managers in making decisions with regard to the serviceability of corrosion-affected concrete structures