The optimization of healing materials used in capsules for effective crack self-healing has garnered significant attention. This study focused on the development of a novel capsule using a full-solid-waste alkali-activated slag system. Instead of traditional cement clinker and chemical agents, healing materials such as red mud, calcium carbide residue, phosphogypsum, and ground granulated blast furnace slag were used. The capsules were autolytic due to the retardation and weak expansion properties of gypsum. The healing mechanisms were mainly attributed to the formation of ettringite and calcium silicate hydrate. Crack width, crack area, and strength recovery tests were used to thoroughly analyze the self-healing behavior of the capsules. Detailed characterizations were conducted to understand the healing products and the evolution process. The results showed that cracks with initial widths less than 350 μm were well-healed, with a healing ratio ranging from 55% to 100% for all cracks (initial widths <600 μm). The cementing characteristics of the healing products were significantly increased by the formation of substantial ettringite, which led to an enhanced strength recovery ratio. Crucially, the composition of the healing products closely resembled the hydrates in the matrix, suggesting that the healed mortar had a high level of system compatibility. These results highlighted the potential of the developed alkali-activated slag capsule in promoting self-healing of cracked cementitious composites.

用于有效裂纹自修复的胶囊中使用的修复材料的优化引起了人们的广泛关注。本研究的重点是使用全固体废物碱激活渣系统开发新型胶囊。使用赤泥、电石渣、磷石膏、磨碎的粒化高炉矿渣等愈合材料代替传统的水泥熟料和化学药剂。由于石膏的阻滞性和弱膨胀特性，胶囊会自溶。愈合机制主要归因于钙矾石和水合硅酸钙的形成。通过裂纹宽度、裂纹面积和强度恢复测试来彻底分析胶囊的自修复行为。进行详细的表征以了解治疗产品和进化过程。结果表明，初始宽度小于350μm的裂纹愈合良好，所有裂纹（初始宽度<600μm）的愈合率在55%~100%之间。大量钙矾石的形成显着提高了修复产品的胶结特性，从而提高了强度恢复率。至关重要的是，修复产品的成分与基质中的水合物非常相似，这表明修复后的砂浆具有高水平的系统相容性。这些结果凸显了所开发的碱激活矿渣胶囊在促进开裂水泥基复合材料自修复方面的潜力。