摘要详情

ID / 提交时间

283 / 2022-10-08 11:55:27

标题

Self-healing of inorganic porous aggregate in concrete: Methods, Characterization and Application

关键字

Concrete,Inorganic materials,Self-healing materials,Aggregate,Crack

主题及专题

地聚合物以及其他低碳水泥混凝土

状态

摘要录用

作者

Yuan Fang / Shenzhen University

Heming Sun / Shenzhen University

摘要

In engineering practice, concrete cracks under the compound stress field will significantly accelerate the deterioration rate of concrete durability. However, the efficiency of traditional concrete crack repair methods is low, so concrete self-healing technology, an efficient and convenient crack repair method, has attracted more and more attention. In this paper, self-healing concrete is prepared by using self-healing aggregate instead of traditional crushed stone aggregate. When the self-healing concrete is cracked by external damage, the aggregate is triggered by physical action to break and release the repair agent. Then the repair agent reacts with the cement material in the crack to generate the repaired product to repair the crack. Firstly, the performance of self-healing concrete was tested through the mix's working and mechanical properties tests. It was found that the self-healing aggregate completely replacing the traditional aggregate had no significant impact on the impermeability of concrete and the functional performance of the mix, and the mechanical properties of the concrete matrix were improved. After that, the image method, microscope observation method and backscattering scanning electron microscope (BSE) were used to study the repair effect of the fracture. The results show that when the crack width is less than 300 μm, the crack repair effect within 15 mm depth is good, the flexural strength recovers to 40.8% at seven days of age, and the area repair rate reaches 100%. At the age of 28 days, the flexural strength recovery rate reached 83.1%, and the impermeable pressure value recovered by 45 %. Using self-repairing aggregate can achieve the purpose of self-repairing concrete cracks, and the repaired product has a good interface with the concrete matrix. The results of this study provide a new idea for concrete self-healing technology.