Superabsorbent polymers (SAPs) are used to counteract self-desiccation in order to mitigate autogenous shrinkage, a problem in cementitious systems with a low water-to-cement ratio. The release kinetics during internal curing are of importance as not all SAP types are able to efficiently mitigate autogenous shrinkage. In this study, neutron tomography is used to study and visualize the water release kinetics over time. Per-voxel analysis of the time-attenuation curve was performed using piecewise-constant functions. Two different SAP types were studied, one being able to mitigate autogenous shrinkage and one quickly releasing its stored water after final setting. The tomography results correspond to autogenous shrinkage measurements and nuclear magnetic resonance tests. The visualization provides information on the time of water release by the SAPs after setting and the time window of internal curing. This opens additional insights towards the application of SAPs in the construction sector and provides information on the mechanism of internal curing.

高吸水性聚合物 (SAP) 用于抵消自干燥，以减轻自收缩，这是水灰比低的水泥体系中的一个问题。内部固化过程中的释放动力学很重要，因为并非所有 SAP 类型都能有效减轻自收缩。在这项研究中，中子断层扫描用于研究和可视化随时间推移的水释放动力学。时间衰减曲线的每体素分析是使用分段常数函数进行的。两种不同类型的SAP进行了研究，一个能够减轻自收缩和一个后终凝迅速释放其储存的水。断层扫描结果对应于自体收缩测量和核磁共振测试。可视化提供了有关固化后 SAP 释放水的时间和内部固化时间窗口的信息。这为 SAP 在建筑领域的应用开辟了更多见解，并提供了有关内部固化机制的信息。