Superabsorbent polymer (SAP) has been applied in alkali-activated slag (AAS) for internal curing, but its interaction mechanism remains unclear. This study employed SAP of a large size (∼2mm) to achieve in-situ and continuous observation of SAP behaviors in AAS paste and their impacts on the surrounding matrix for 90 days. Results showed that SAP in AAS exhibited different dynamics over time: swelling (0–10h), fast deswelling (10h–48h), and slow deswelling (48h-90d). The progress of AAS hydration determines the onset and rate of SAP deswelling. SAP swelling inhibited the hydration of AAS but had little effect on the long-term reaction degree due to the ion release during deswelling. Some Ca ions were retained in SAP, altering the reaction products of AAS by forming N-A-S-H gels. The effects of SAP on AAS diminish over distance, forming an annular affected zone approximately 50 % of the maximum swelling radius of SAP, characterized by a dense microstructure.

高吸水性聚合物（SAP）已应用于碱激活矿渣（AAS）的内部固化，但其相互作用机制仍不清楚。本研究采用大尺寸（∼2mm）的 SAP 来实现 90 天的原位连续观察 AAS 浆料中 SAP 的行为及其对周围基质的影响。结果显示，AAS 中的 SAP 随着时间的推移表现出不同的动态：溶胀（0-10 小时）、快速消溶胀（10-48 小时）和缓慢消溶胀（48 小时-90 天）。AAS 水合的进展决定 SAP 消溶胀的开始和速率。SAP溶胀抑制了AAS的水化，但由于消溶胀过程中离子的释放，对长期反应程度影响不大。一些 Ca 离子保留在 SAP 中，通过形成 NASH 凝胶来改变 AAS 的反应产物。SAP 对 AAS 的影响随着距离的增加而减弱，形成一个大约为 SAP 最大膨胀半径 50% 的环形影响区，其特点是致密的微观结构。