Title: Updating of chloride ingress models using core data measurements

Authors: Robert Wolofsky; Luc Chouinard; David Conciatori; Josée Bastien

Addresses: Pöyry (Montreal) Inc., 5250 rue Ferrier, Montreal, Quebec, Canada ' Department of Civil Engineering and Applied Mechanics, McGill University, 817 Sherbrooke Street West, Montreal, Quebec, Canada ' Département de génie civil et de génie des eaux, Université Laval, Pavillon Adrien-Pouliot, 1065 Avenue de la Médecine, Québec, Canada ' Département de génie civil et de génie des eaux, Université Laval, Pavillon Adrien-Pouliot, 1065 Avenue de la Médecine, Québec, Canada

Abstract: A large proportion of concrete bridges in North America are reaching the end of their service life. An important factor that accelerates deterioration is the amount of salts used during winter months. The chloride ions from the salt enter the concrete and destroy the passive-oxide layer that protects the reinforcing steel from corrosion. The TransChlor® software is used to simulate the time history of chloride ion ingress into a typical concrete bridge. A climate model is used to simulate the exposure of the structure to winter conditions. A probabilistic method is used to propagate the uncertainty on material properties in the model and to obtain the distribution of chloride ion concentrations. A procedure for updating the distribution is proposed using data from core samples at two depths (25/50 mm) and for the two types of exposure (splash/direct). The procedure is shown to be very efficient in reducing bias and variance from model predictions.

Keywords: concrete bridges; deterioration; corrosion initiation; updating; uncertainty propagation; chloride ingress models; core data measurement; modelling; salt; passive oxide layer; reinforcing steel protection; simulation; climate models; winter conditions; material properties.

DOI: 10.1504/IJRS.2015.073136

International Journal of Reliability and Safety, 2015 Vol.9 No.4, pp.291 - 310

Available online: 20 Nov 2015 *

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