Structural reliability of concrete bridges including improved chloride-induced corrosion models Kim Anh T. Vu, Mark G. Stewart * Department of Civil, Surveying and Environmental Engineering, The University of Newcastle, Rankin Drive, Newcastle, NSW 2308, Australia Abstract A structural deterioration reliability (probabilistic) model has been used herein to calculate probabilities of structural failure. New reinforced concrete corrosion initiation, corrosion rate and time-variant load models are proposed. Three durability design speci®cations are considered in a lifetime reliability analysis of a RC slab bridge. Time-variant increases in loads are considered also. It was found that the application of de-icing salts causes signi®cant long-term deterioration and reduction in structural safety for poor dur- ability design speci®cations. A reduced cover or increased water-cement ratio increases failure prob- abilities. When compared to the case of ``no deterioration'', it was observed also that the probability of failure only marginally increased for good durability design speci®cations. The approaches described herein are relevant to other physical infrastructure also. # 2000 Elsevier Science Ltd. All rights reserved. Keywords: Structural reliability; Deterioration; Corrosion; Reinforced concrete; Bridges 1. Introduction Poor concrete durability and corrosion of reinforcement bars are the primary cause of struc- tural deterioration of bridge decks, piers and other structures. Corrosion-initiated longitudinal cracking and associated spalling of the concrete cover are particularly common problems in concrete structures. Corrosion is initiated mainly by chloride contamination, often in conjunction with inadequate cover or poor quality concrete. Chlorides may diuse through the protective concrete cover or corrosion may be initiated also by cracking. Reinforcement corrosion causes loss of area (metal loss) and the increased volume of corrosion products (rust) causes concrete tensile stresses that may be suciently large to cause internal microcracking, external longitudinal 0167-4730/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII: S0167-4730(00)00018-7 Structural Safety 22 (2000) 313±333 www.elsevier.nl/locate/strusafe * Corresponding author. Tel.: +61-2-4921-6027; fax: +61-2-4921-6991. E-mail address: mark.stewart@newcastle.edu.au (M.G. Stewart).