Reliability analysis of corroding RC members using adaptive Response Surface

Rebar corrosion is the most commonly observed deterioration mechanism in reinforced concrete (RC) structures leading to inadequate performance (e.g. increased deflections, loss of load capacity). Reliability analysis is a widely proposed tool to assess corroding RC structures, underpinning uncertainties inquantifying the deterioration processes. Often, second moment methods such as FORM/SORM are used for the probabilistic performance assessment. These methods, however, require the performance function of the structure expressed in explicit form. Non-linear finite element analysis (NLFEA), an effective tool to model in detail the structural degradation mechanisms, yields the performance function an implicit form. In this paper, an adaptive procedure is presented for reliability analysis, which utilizes NLFEA and response surface method (RSM). The procedure is demonstrated through a case study using a corroding RC beam. The variation of concrete properties, impaired mechanical properties of the corroded rebars and bond deterioration are considered in the analysis. Results are presented for the load capacity and ductility limit states