Cracks in concrete structures reduce bearing capacity, durability, and safety. This paper reveals the effect of superabsorbent polymers (SAP) on the self-healing property of pre-damaged concrete based on mechanical properties tests, mercury intrusion porosimetry, scanning electron microscopy, and energy dispersive spectrometer. The experimental results show that SAP reduces the mechanical properties of the SAP-modified concrete under the same W/C ratio, but a small amount of SAP can improve the later strength under the 0.35 W/C ratio. The addition of SAP increased the volume of small capillary pores (100 μm) and significantly reduced the former with an increase in age. The SEM-EDS analysis indicates that the water released by SAP promotes the formation of C-S-H gel. AFt in the cracks is the main reason for self-healing, and the addition of CO₂ to produce calcium carbonate is another one. Furthermore, this study finds that SAP-modified concrete has the best self-healing effect and the densest structure when the W/C ratio is 0.35 and the SAP content is 0.25%. The self-healing performance makes the SAP-modified concrete have broad application prospects.

As carbon-based nanomaterials, water-soluble C₆₀ derivatives have potential applications in various fields of biomedicine. In this study, a water-soluble fullerene C₆₀ derivative bearing alanine residues (Ala-C₆₀) was synthesized. The effects of Ala-C₆₀ on neural stem cells (NSCs) as seed cells were explored. Ala-C₆₀ can promote the proliferation of NSCs, induce NSCs to differentiate into neurons, and inhibit the migration of NSCs. Most importantly, the Ala-C₆₀ can significantly increase the cell viability of NSCs treated with hydrogen peroxide (H₂O₂). The glutathioneperoxidase (GSH-Px) and superoxide dismutase (SOD) activities and glutathione (GSH) content increased significantly in NSCs treated even by 20 μM Ala-C₆₀. These findings strongly indicate that Ala-C₆₀ has high potential to be applied as a scaffold with NSCs for regeneration in nerve tissue engineering for diseases related to the nervous system.

This study aims to prepare an anti-washout grout using marine soft clay to stabilize the wind power pile foundations. The cement, hydroxypropyl-methyl cellulose ether (HPMC), and sodium silicate were chosen as the main materials to modify the marine soft clay, and the fluidity, bleeding rate, setting time, rheology, anti-washout characteristics, and compressive strength were investigated. The results showed that high cement content, HPMC, and sodium silicate decreased the workability of grout while enhancing the washout resistance. The addition of HPMC and sodium silicate would increase the yield stress and plastic viscosity of the grout. The sodium silicate content was the key factor influencing the early strength, while the cement content and HPMC affect the later strength. The microstructures including the morphology of C-S-H gels and the content of ettringite and calcium hydroxide significantly changed with the addition of sodium silicate, and Friedel’s salt was observed through the microstructure analysis. This study can provide effective guidance for the utilization of marine soft clay, the preparation of anti-washout grout, and the control of pile foundation stability.

Operating tunnels are often located in complex geological conditions and are prone to various types of damage. Even after structural repair, the repaired material may be vulnerable to secondary damage. It is difficult to effectively repair operating tunnel damage. Hence, developing high-performance repair materials for tunnel structures is critical. This study aimed to develop repair materials by studying the synergistic effects of fiber and polymers. The effect of polyvinyl alcohol (PVA) fiber and PTB (COMPAKTUNA.PRO) emulsion on the compressive strength (40 × 40 × 40 mm, GB/T 17671-2020), flexural strength (40 × 40 × 160 mm, GB/T 17671-2020), uniaxial tensile properties (330 × 60 × 13 mm, JC/T 2461-2018), bond strength (40 × 40 × 160 mm, JC/T 2537-2019), rapid chloride migration coefficient (φ100 × 50 mm, GB/T 50082-2009), porosity (40 × 40 × 40 mm, SY/T 6490-2014), and scanning electron microscopy (less than 1 cm³, GB/T 27788-2020) was analysed. The test was completed in the laboratory of our school, and the average value of three specimens per mix ratio was taken. The results indicate that both PVA fiber and PTB emulsion addition reduce the compressive strength but significantly increase the flexural strength, tensile strength, and ultimate tensile strain of cementitious composite. The compressive-to-flexural strength ratio decreases, and the uniaxial compression toughness index increases. The cementitious composites exhibit good integrity after damage. The influence of the PVA fiber is more potent than that of the PTB emulsion. The PTB emulsion increases the impermeability and bonding strength of the cementitious composite and can improve the disadvantages caused by adding the PVA fibers. The bridging effect of the PVA fiber and the membrane-forming effect of the PTB emulsion together influence the performance and cause a synergistic effect to achieve superposition and complementation of advantages. The optimal content of the PVA fiber and PTB emulsion under the synergistic effect can be obtained. The findings can provide a theoretical basis for the optimal design and practical application of restoration materials.