A new self-healing agent for accelerating the healing kinetics while simultaneously binding seawater ions in cracked cement paste

作者：Wu, Xintong; Huang, Haoliang^*; Liu, Hao; Hu, Jie; Wu, Kai; Wei, Jiangxiong; Yu, Qijun

来源：Materials Letters, 2021, 283: 128884.

DOI：10.1016/j.matlet.2020.128884

• Rapid self-healing
• Chemical binding
• Aggressive ions
• Seawater
• Composite materials
• Defects

To mitigate the corrosion of steel bars and the erosion of the matrix in cracked reinforced concrete in a marine environment, a new self-healing agent was developed that can not only chemically bind the invading ions in the cracks, but also accelerate the crack closure. The closure ratio of a crack with an initial width of 400 mu m can reach 80% after self-healing for 1 day when the developed CaO-NaAlO2 healing agent was added into the concrete with a dosage of 5% by volume. The value for the references without the self-healing was only about 20%. The fast sealing of cracks can rapidly stop the further ingress of these ions. Moreover, reaction products of self-healing, such as Friedel's salt, Kuzel's salt and brucite, were detected, which indicates that Cl-, SO42- and Mg2+y ions invading into the cracks were bound chemically. Therefore, the risk of steel bar corrosion was decreased.

• 单位
  同济大学