Prediction model of long-term chloride diffusion into plain concrete considering the effect of the heterogeneity of materials exposed to marine tidal zone

• Published in: Construction & building materials 2018-01, Vol.159, p.297-315
• Main Authors: Wang, Yuanzhan, Wu, Linjian, Wang, Yuchi, Li, Qingmei, Xiao, Zhong
• Format: Article
• Language: English
• Subjects: Analysis; Chemical properties; Chlorides; Concrete; Concretes; Heterogeneity; Long-term chloride diffusion; Marine tidal zone; Prediction model; Steel corrosion
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2017.10.083

•Chloride diffusion in concrete considering heterogeneity of materials is studied.•Long-term meso-scopic numerical simulation for chloride transport is proposed.•A simple empirical prediction model for long-term chloride diffusion is developed.•Cs and D change over time and volume fraction of coarse aggregate in tidal zone. Long-term chloride-induced corrosion of steel reinforcement would make concrete structures vulnerable to deterioration and as a result shorten their service life. However, physical experiment of in-situ or laboratory may not be an effective way to determine long-term chloride profiles and diffusion behaviors into concrete attributed to its time-consuming and implementary difficulty. This study adopted the results of chloride concentration into mortar and corresponding concrete specimens from a filed experiment in marine tidal zone at exposure times of 60, 120, 240, 360, 480, and 600 d reported in literatures, and the meso-scopic finite element numerical simulation method, in which the concrete was modeled as a three-phase composite material composed of mortar, coarse aggregate, and interfacial transition zone (ITZ), was combined to develop a simplified empirical model for predicting long-term chloride diffusion into plain concrete considering the effect of the heterogeneity of materials exposed to marine tidal zone (with exposure limited to 20 years). Certainly, the accuracy, reasonability and reliability of the evaluated chloride profile results associated with this empirical prediction model were validated as well. The proposed empirical model is expected to be useful in realistically predicting the long-term diffusion of chloride into concrete.