Reactions of self-healing agents and the chemical binding of aggressive ions in sea water

Thermodynamics and kinetics

Journal article (2021)

Authors

Xintong Wu South China University of Technology
Haoliang Huang South China University of Technology, Guangdong Low Carbon Technologies Engineering Centre for Building Materials
Hao Li South China University of Technology
Jie Hu South China University of Technology, Guangdong Low Carbon Technologies Engineering Centre for Building Materials
Jiangxiong Wei South China University of Technology, Guangdong Low Carbon Technologies Engineering Centre for Building Materials
Zhengwu Jiang Tongji University
G. Ye Materials and Environment - CEG
Qijun Yu Guangdong Low Carbon Technologies Engineering Centre for Building Materials, South China University of Technology
Barbara Lothenbach Swiss Federal Laboratories for Materials Science and Technology (Empa)
Research Group
Materials and Environment (CEG) (TU Delft)
Copyright: © 2021 Xintong Wu, Haoliang Huang, Hao Liu, Jie Hu, Jiangxiong Wei, Zhengwu Jiang, G. Ye, Qijun Yu, Barbara Lothenbach
DOI
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https://doi.org/10.1016/j.cemconres.2021.106450
Self-healing Cementitious materials Thermodynamic modeling Marine environment Ion binding
More Info
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Published Date

2021

Language

English

Faculty

Civil Engineering & Geosciences

Department

Materials- Mechanics- Management & Design

Research Group

Materials and Environment

Abstract

New self-healing agents that can chemically bind seawater ions invading cracked cementitious materials were proposed. The potential of self-healing and binding of seawater ions were investigated by thermodynamic modeling. It was found that CaO-NaAlO2 and CaO-metakaolin agents can have Cl−, SO42− and Mg2+ chemically bound by reacting with sea water to form Friedel's salt, Kuzel's salt, ettringite and hydrotalcite. The removal of Cl− from seawater firstly increased and then decreased with the increase of Ca/Al molar ratio in both agents, while the removal of Mg2+ and SO42− were hardly influenced and approximated 100%. Because NaAlO2 dissolves and releases Al(OH)4− rapidly, precipitates binding Cl−, SO42− and Mg2+ were formed fast. In comparison, the reaction of metakaolin binding aggressive ions occurred after 3 days. Because of the faster reaction and the capacity to make [Cl−]/[OH−] lower in the solution, CaO-NaAlO2 would be more efficient for self-healing and mitigating reinforcement corrossion than CaO-metakaolin.