TY - JOUR
T1 - Reactions of self-healing agents and the chemical binding of aggressive ions in sea water
T2 - Thermodynamics and kinetics
AU - Wu, Xintong
AU - Huang, Haoliang
AU - Liu, Hao
AU - Hu, Jie
AU - Wei, Jiangxiong
AU - Jiang, Zhengwu
AU - Ye, Guang
AU - Yu, Qijun
AU - Lothenbach, Barbara
N1 - Accepted Author Manuscript
PY - 2021
Y1 - 2021
N2 - 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.
AB - 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.
KW - Cementitious materials
KW - Ion binding
KW - Marine environment
KW - Self-healing
KW - Thermodynamic modeling
UR - http://www.scopus.com/inward/record.url?scp=85105076536&partnerID=8YFLogxK
U2 - 10.1016/j.cemconres.2021.106450
DO - 10.1016/j.cemconres.2021.106450
M3 - Article
AN - SCOPUS:85105076536
SN - 0008-8846
VL - 145
SP - 1
EP - 13
JO - Cement and Concrete Research
JF - Cement and Concrete Research
M1 - 106450
ER -
