In this paper, basic creep mechanism of ambient cured one-part alkali activated slag-fly ash (AASF) paste is examined at the microscopic level. A special mini creep rig is constructed enabling in-situ monitoring of water redistribution over time between high- and low-density (HD, LD) gel pores within the loaded paste specimens using 1H NMR relaxometry. The results suggest that the contraction of C-(N)-A-S-H particles is accompanied by the reduction of water content in HD gel for loaded AASF paste. In contrast, in the loaded OPC paste a noticeable decrease of water residing in LD rather than HD C-S-H gel was observed, implying the presence of a distinct creep mechanism. In addition to the different water environment, the more crosslinked bonding structure of AASF could partially account for its lower creep response supported by 29Si NMR measurement. The findings of this study provide evidence in understanding underlying basic creep mechanism of AASF.

中文翻译：

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单组分碱活性渣和粉煤灰浆的基本蠕变机理新见解


本文在微观层面上研究了常温固化单组分碱活性矿渣粉煤灰 （AASF） 浆料的基本蠕变机理。构建了一个特殊的微型蠕变装置，能够使用 1H NMR 弛豫法对加载的糊状样品内高密度和低密度 （HD， LD） 凝胶孔之间的水随时间的重新分布进行原位监测。结果表明，对于负载的 AASF 糊剂，C-（N）-A-S-H 颗粒的收缩伴随着 HD 凝胶中水分含量的降低。相比之下，在负载的 OPC 浆料中，观察到 LD 而不是 HD C-S-H 凝胶中的水明显减少，这意味着存在明显的蠕变机制。除了不同的水环境外，AASF 的交联键合结构更多，部分原因在于 29Si NMR 测量支持其较低的蠕变响应。本研究的结果为理解 AASF 的潜在基本蠕变机制提供了证据。