Reliability analysis of corroding RC members using adaptive Response Surface Method

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 in quantifying the deterioration processes. FORM/SORM are computationally efficient methods for the probabilistic performance assessment of the structure especially when the performance function is 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 in 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.