Spatial variability of pitting corrosion and its influence on structural fragility and reliability of RC beams in flexure Mark G. Stewart * Centre for Infrastructure Performance and Reliability, Department of Civil, Surveying and Environmental Engineering, School of Engineering, The University of Newcastle, Rankin Drive Callaghan, NSW 2308, Australia Received 26 May 2003; received in revised form 26 January 2004 Abstract A stochastic process for assessing the effect of spatial variability of pitting corrosion on structural re- liability and fragility is developed for singly reinforced simply supported reinforced concrete (RC) beams in flexure. A distribution of pitting corrosion is inferred from existing literature. The RC beam is discretised into a series of elements and maximum pit depths are generated for each reinforcing steel bar in each el- ement. The analysis considered various member spans, loading ratios, bar diameters and number of bars in a given cross-section. Comparisons made with general corrosion showed that pitting corrosion is more critical for smaller diameter reinforcing steel bars. It was also found that up to a three-fold increase in 50- year probabilities of failure were observed if spatial variability of pitting corrosion are included in the analysis when compared to probabilities of failure based on the mid-span limit states only. This strongly suggests that the inclusion of spatial variability of pitting corrosion can lead to significant decreases in structural reliability for flexural RC members. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Reinforced concrete; Pitting corrosion; Spatial variability; Structural reliability; Fragility analysis 1. Introduction A typical characteristic of deterioration of structures exposed to aggressive chloride environ- ments is pitting (or localised) corrosion of the reinforcing steel. General corrosion tends to occur * Tel.: +61-2-4921-6027; fax: +61-2-4921-6991. E-mail address: mark.stewart@newcastle.edu.au (M.G. Stewart). 0167-4730/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.strusafe.2004.03.002 Structural Safety 26 (2004) 453–470 www.elsevier.com/locate/strusafe STRUCTURAL SAFETY