Effect of chloride binding and sulfate ion attack on the chloride diffusion in calcium sulfoaluminate-based material under seawater environment

Bibliographic Details
Title: Effect of chloride binding and sulfate ion attack on the chloride diffusion in calcium sulfoaluminate-based material under seawater environment
Authors: Xin Qiu, Jingqiang Yuan, Weizhong Chen, Xianjun Tan, Guojun Wu, Hongming Tian
Source: Journal of Materials Research and Technology, Vol 30, Iss , Pp 4261-4271 (2024)
Publisher Information: Elsevier, 2024.
Publication Year: 2024
Collection: LCC:Mining engineering. Metallurgy
Subject Terms: Chloride binding, Sulfate ion, Calcium sulfoaluminate cement, Isothermal adsorption models, Chloride ion diffusion, Mining engineering. Metallurgy, TN1-997
More Details: The diffusion of chloride ions in reinforced concrete under the seawater environment will affect the physical or mechanical properties and durability. Sulfate ions also influence the diffusion of chloride ions by generating expansion products through physical and chemical reactions. Further research on the effects of chloride binding and sulfate ion attack on chloride ion diffusion will deepen the understanding of concrete failure mechanism. In this paper, a quaternary blend based on calcium sulfoaluminate (CSA) cement was prepared and laboratory immersion tests were conducted in artificial seawater with varying salt concentrations. Initially, chloride ion concentration measurements and XRD tests were conducted at different corrosion ages and salt concentrations. Subsequently, the chloride binding properties of CSA-based materials was quantified through the analysis of chloride ion concentration and the phases of hydration products. Meanwhile, the corrosive effect of sulfate ions on chloride ion diffusion was determined corresponds to the content of expansive hydration products. Furthermore, numerical simulations were employed to evaluate the impact of sulfate ion corrosion, chloride binding, and their combined effects on chloride ion diffusion, and the results were compared with free chloride ion concentration (Cf). The results indicate that the total chloride ion concentration (Ct) exhibits a linear relationship with increasing salt concentrations of seawater in CSA-based materials. Meanwhile, the bound chloride ion concentration (Cb) follows a logarithmic growth pattern. The chloride binding rate experiences a linear decline with the increase of chloride ion concentration in the artificial seawater. Additionally, the relationship between Cf and Cb or Ct can be described using different isothermal adsorption models for the CSA-based materials. Among these models, the Langmuir model is suitable for characterizing the relationship between Cf and Cb, while the Freundlich model is suitable for describing the relationship between Cf and Ct. Furthermore, it is noteworthy that sulfate ion attack and chloride binding exert nearly equivalent effects on the diffusion of chloride ions in CSA-based materials at short corrosion age and low chloride ion concentration. However, the corrosive impact of sulfate ions gradually evolves into the dominant factor in the progression of corrosion over time and the increase in seawater salt concentration.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2238-7854
Relation: http://www.sciencedirect.com/science/article/pii/S223878542400913X; https://doaj.org/toc/2238-7854
DOI: 10.1016/j.jmrt.2024.04.139
Access URL: https://doaj.org/article/f8e64ec04bb94976adf9ce529db65709
Accession Number: edsdoj.f8e64ec04bb94976adf9ce529db65709
Database: Directory of Open Access Journals
More Details
ISSN:22387854
DOI:10.1016/j.jmrt.2024.04.139
Published in:Journal of Materials Research and Technology
Language:English