Biomimetic anisotropic hydrogel as a smart self-healing agent of sustainable cement-based infrastructure

• Published in: Cement & concrete composites Vol. 154; p. 105763
• Main Authors: Liu, Ming, Hu, Miaomiao, Zou, Shuang, Lu, Haichuan, Yu, Jiayu, Guo, Jintang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2024
• Subjects: Anisotropic hydrogel; Performance recovery; Self-healing cementitious materials; Sustainability; Performance recovery; Anisotropic hydrogel; Self-healing cementitious materials; Sustainability
• ISSN: 0958-9465
• DOI: 10.1016/j.cemconcomp.2024.105763

The durability improvement of cement-based infrastructure is an effective strategy to achieve sustainable development and reduce the carbon footprint. In this work, a biomimetic anisotropic hydrogel, alginate/polyacrylamide/halloysite nanotubes hybrid hydrogel (SA/AM/HNTs-RDC), was fabricated as a self-healing agent to enhance the self-healing ability and extend the service life of cement-based infrastructure. The effects of SA/AM/HNTs-RDC hydrogel on the formation and deposition of healing products and the self-healing behavior of cement in the different conditions (water condition and CO2-rich condition) were investigated. Compared with the matrix hydrogel (alginate/polyacrylamide, SA/AM), the crosslinking ions and anisotropic microstructure of SA/AM/HNTs-RDC hydrogel can stimulate the massive formation and dense deposition of healing products (ettringite (AFt) and monosulfo aluminate (AFm) in the simulated water condition, calcite and AFt in CO2-rich condition) to accelerate the performance recovery of the damaged construction. The self-healing measurements exhibited that the cracks around 200 μm in the cement paste with 1 % anisotropic hydrogel (RDC1) can be sealed completely after 14-day-curing in water, and its recovery ratio of the compressive strength increased by about 10 % compared with control samples. In CO2-rich condition, the closure rate of cracks was accelerated and the complete healing of cracks with similar width only needed 7 days. The compressive strength recovery increased by 13.7 % over control samples. [Display omitted] •Lifetime extension of construction is imperative to mitigate environmental burden.•SA/AM/HNTs-RDC stimulates massive formation and deposition of healing products.•The optimized precipitation enhances the performance recovery of damaged area.•SA/AM/HNTs-RDC endows cement matrix with an excellent self-healing behavior.•This work provides a promising candidate for sustainable cementitious composites.