Influence of the rainfall intensity on the chloride ion distribution in concrete with different levels of initial water saturation

• Published in: Construction & building materials 2021-04, Vol.281, p.122561, Article 122561
• Main Authors: Jin, Hesong, Liu, Jiaying, Jiang, Zhilu, Zhou, Hao, Liu, Jun
• Format: Article
• Language: English
• Subjects: Chloride ion distribution; MIP; Rainfall intensity; Saturation; SEM
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2021.122561

•The rainfall environment was simulated in the laboratory.•The influence of rainfall intensity on the distribution of chloride ions in concrete was studied.•The distribution of chloride ions in concrete under different saturations was discussed.•In this environment, the relationship between total chloride ion and free chloride ion in concrete is analyzed.•The SEM, MIP and XRD phase analysis of the compounds under different rainfall intensities were explored. Reinforced concrete (RC) structures located in coastal salt spray areas are subjected to rainfall erosion and chloride ion corrosion throughout the year. Consequently, this study simulates a rainfall environment with artificial rainfall simulation devices and applies a potentiometer to determine the chloride ion concentration. The microstructures and chemical compositions of the concrete were revealed through microscopic experiments. The research results show that with a greater rainfall intensity, the surface chloride ion concentration decreases more obviously, the surface chloride ion loss is more serious, and the chloride ion binding capacity becomes weaker. As the saturation decreases, the binding capacity of chloride ions also decreases. This study can provide some theoretical ideas for the durability design of PC structures in rainy environments.