基于微生物-海藻酸钠的外修复材料及其协同修复裂缝效果

To address the technical challenge of the slow repair rate of microbial-based exo-remediation materials, microbial-sodium alginate exo-remediation materials were prepared by adding different concentrations (0.0%, 0.5%, 1.0%, 1.5% and 2.0%) of sodium alginate to the existing microbial exo-remediation material, and analyzed their properties and synergistic exo-remediation effect. The results show that the viscosity of the microbial-sodium alginate exo-remediation materials increases, while the flow rate decreases as sodium alginate concentration increases; the repair product formed by the microbial-sodium alginate external repair material is white in color and has a certain elasticity, and the composition of the repair product is mainly calcium carbonate, while the calcium alginate gel formed is filled in the gaps between calcium carbonate particles; and for different crack widths, the microbial calcium alginate hydrogel formed by microbial-sodium alginate external repair material can achieve instant plugging, resulting in a lower water penetration coefficient and a higher compressive strength. In particular, the optimum repair effect for 1.0 mm cracks can be achieved at a sodium alginate concentration of 0.5%, which reduces the water penetration coefficient from 9.76 to 0 under a maintained water pressure of 1 kPa, and achieves a strength recovery rate at 7 d of 22.7%.