Propagation Time for Carbonation- and Chloride -induced Corrosion

Propagation Time for Carbonation- (and Chloride)-induced Corrosion 

Defining the end of the propagation period should be based on either (ranked by length) appearance of the first crack, spalling of the concrete cover, or unacceptable loss of cross section. Because propagation until any of these events involves many complex processes and factors, accurate modelling is on the border of our present capabilities. The DuraCrete model for corrosion propagation is summarised here. 

A Hmit state related to corrosion propagation considered in DuraCrete is the appearance of a crack with a width of 1 mm, which is taken as the start of spaUing. Equations are given [21] for the crack width caused by a corroding bar based on the amount of corrosion present, the amount needed to produce a crack, and some factors including the cover depth, the rebar diameter and the tensile strength of the concrete. After corrosion initiation, the amount of corrosion is given by the corro- 

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