Chloride-induced corrosion of steel in cracked concrete-Part II: Corrosion rate prediction models

摘要

Chloride-induced corrosion rate (i(corr)) prediction models for RC structures in the marine tidal zone that incorporate the influence of crack width (w(cr)), cover (c) and concrete quality are proposed. Parallel corrosion experiments were carried out for 2 1/4 years by exposing one half of 210 beam specimens (120 x 130 x 375 mm long) to accelerated laboratory corrosion (cyclic wetting and drying) while the other half underwent natural corrosion in the tidal zone. Experimental variables were w(cr) (0, incipient crack, 0.4, 0.7 mm), c (20,40 mm), binder type (PC, PC/GGBS, PC/FA) and w/b ratio (0.40, 0.55). The two proposed models (one each for accelerated and natural i(corr)) can aid not only in quantifying the propagation phase, but also provide a novel way to select c, w(cr) and concrete quality. (C) 2015 Elsevier Ltd. All rights reserved.