Re-swelling capacity is a key factor affecting the contribution of superabsorbent polymers (SAPs) to sealing cracks in concrete. In this paper, a new parameter (η), the ratio between the volume of the crack filled with the expansive SAPs and the volume of dry SAPs, is given to evaluate the re-swelling capacity of a single SAPs particle. Moreover, the influences of paste composition, solution properties, and crack width on the η value are studied by an innovative immersion test. The results show that the swollen volume ratio, the ratio of the swollen volume of SAPs during mixing to their dry volume, decreases with the reduction of the water-to-binder ratio and the addition of mineral admixtures. Furthermore, the swollen volume ratio, the solution properties, and the crack width have significant impacts on the η value. The η value rises with an increase in crack width (0.25–1 mm), revealing the restricting effects of cracks on the re-swelling capacity of SAPs. These results indicate that the paste composition, solution properties, and crack width should be considered when designing the self-sealing concrete containing SAPs.

中文翻译：

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具有人工裂缝的硬化水泥浆中高吸水性聚合物 (SAPs) 的再膨胀行为

再膨胀能力是影响超吸水聚合物 (SAP) 对混凝土裂缝密封作用的关键因素。在本文中，给出了一个新参数（η），即填充膨胀 SAPs 的裂缝体积与干 SAPs 体积之间的比值，用于评估单个 SAPs 颗粒的再膨胀能力。此外，通过创新的浸入试验研究了膏体成分、溶液性质和裂纹宽度对 η 值的影响。结果表明，溶胀体积比，即混合过程中 SAPs 的溶胀体积与其干体积的比值，随着水与粘合剂比的降低和矿物掺合料的加入而降低。此外，溶胀体积比、溶液性质和裂纹宽度对 η 值有显着影响。η 值随着裂纹宽度的增加（0.25-1 mm）而增加，揭示了裂纹对 SAPs 再膨胀能力的限制作用。这些结果表明，在设计含有 SAPs 的自密封混凝土时，应考虑膏体成分、溶液性质和裂缝宽度。