Abstract This paper monitored the viscoelasticity development of fresh C3A-gypsum paste in situ by small amplitude oscillation shear (SAOS) within 5 h. The development of viscoelasticity of paste with time can be characterized by two different stages. Isothermal microcalorimetry, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and low field 1H nuclear magnetic resonance (NMR) measurements were used to investigate the underlying mechanisms behind these two stages. It was found that the first stage is governed by the increase of solid volume fraction while the second stage is controlled by the rigidification of ettringite networks. The growth of loss modulus is restricted since the formation of ettringite linkages between particles. Moreover, the considerable elasticity development of fresh C3A-gypsum paste is stemmed directly from the increasing ettringite precipitation.

中文翻译：

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了解新鲜 C3A-石膏浆随时间变化的粘弹性背后的机制

摘要 本文通过小振幅振荡剪切（SAOS）在5 h内原位监测新鲜C3A-石膏糊的粘弹性发展。糊状物的粘弹性随时间的发展可分为两个不同的阶段。等温微量热法、X 射线衍射 (XRD)、扫描电子显微镜 (SEM) 和低场 1 H 核磁共振 (NMR) 测量用于研究这两个阶段背后的潜在机制。发现第一阶段由固体体积分数的增加控制，而第二阶段由钙矾石网络的硬化控制。由于颗粒之间形成钙矾石键，损耗模量的增长受到限制。而且，