Strength and hydration products of reactive MgO-silica pastes
Strength and hydration products of reactive MgO-silica pastes
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DOI：
10.1016/j.cemconcomp.2014.04.003
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发表时间：
2014-09-01
影响因子：
10.5
通讯作者：
Al-Tabbaa, Abir
中科院分区：
文献类型：
--
作者：
Jin, Fei;Al-Tabbaa, Abir
许多研究者研究了氧化镁与微二氧化硅的反应，证实了水合硅酸镁的形成。据报道，该混合物具有作为建筑和环境用途的新型材料的潜力。但MgO的反应性、纯度等特性差异较大，会对MgO-silica共混物的水化过程产生影响。研究了反应性氧化镁和二氧化硅共混物在室温下90天的强度和水化产物。通过红外光谱、热重分析和x射线衍射等手段证实了固化7天后硅酸镁水合物的存在。利用扫描电子显微镜和能谱仪对制备的水合硅酸镁进行了微观结构和元素分析。此外，还讨论了氧化镁的特性对水化过程的影响。结果表明，水合硅酸镁的合成高度依赖于前驱体的反应活性。MgO和二氧化硅的反应活性越高，水合硅酸镁的生成速率越高。此外，氧化镁中的杂质影响了共混物的pH值，而pH值又决定了二氧化硅的溶解度和水合硅酸镁的形成。(C) 2014 Elsevier Ltd.版权所有。
The reaction between MgO and microsilica has been studied by many researchers, who confirmed the formation of magnesium silicate hydrate. The blend was reported to have the potential as a novel material for construction and environment purposes. However, the characteristics of MgO vary significantly, e.g., reactivity and purity, which would have an effect on the hydration process of MgO-silica blend. This paper investigated the strength and hydration products of reactive MgO and silica blend at room temperature up to 90 days. The existence of magnesium silicate hydrate after 7 days' curing was confirmed with the help of infrared spectroscopy, thermogravimetric analysis and X-ray diffraction. The microstructural and elemental analysis of the resulting magnesium silicate hydrate was conducted using scanning electron microscopy and energy dispersive spectroscopy. In addition, the effect of characteristics of MgO on the hydration process was discussed. It was found that the synthesis of magnesium silicate hydrate was highly dependent on the reactivity of the precursors. MgO and silica with higher reactivity resulted in higher formation rate of magnesium silicate hydrate. In addition, the impurity in the MgO affects the pH value of the blends, which in turn determines the solubility of silica and the formation of magnesium silicate hydrate. (C) 2014 Elsevier Ltd. All rights reserved.