In this study, the hydration product, C-S-H density, and pore structure at different layers from the drying surface were measured. Besides, the zone affected by the released internal curing water from SAP was identified by assessing the nanoindentation modulus. The results found that the SAP affected the moisture distribution and changed the evaporation and self-desiccation rates in the inner and outer layers. Such imposed moisture gradients affected the micromechanical properties of UHPC at different layers due to the change in the hydration degree of the binder, the density of C-S-H, and the pore structure of the matrix. The addition of SAP improved the hydration dynamics and transferred the LD C-S-H into HD or UHD C-S-H. As the distance from the drying surface increased, the affected zone of SAP increased from 60 to 120 μm, showing the more effectiveness of SAP at inner layers.

在这项研究中，测量了干燥表面不同层的水化产物、CSH 密度和孔隙结构。此外，通过评估纳米压痕模量确定了受 SAP 释放的内部固化水影响的区域。结果发现，SAP影响了水分分布，改变了内外层的蒸发和自干燥率。由于粘合剂的水合度、CSH 的密度和基质的孔结构的变化，这种施加的水分梯度影响了 UHPC 在不同层的微机械性能。SAP 的添加改善了水合动力学并将 LD CSH 转化为 HD 或 UHD CSH。随着距干燥面距离的增加，SAP 影响区从 60 μm 增加到 120 μm，