Characterisation of reactive magnesia and sodium carbonate-activated fly ash/slag paste blends
Characterisation of reactive magnesia and sodium carbonate-activated fly ash/slag paste blends
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DOI：
10.1016/j.conbuildmat.2015.06.015
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发表时间：
2015-09-15
影响因子：
7.4
通讯作者：
Al-Tabbaa, Abir
中科院分区：
文献类型：
--
作者：
Abdalqader, Ahmed F.;Jin, Fei;Al-Tabbaa, Abir
研究了碱激发粉煤灰(FA)/矿渣(AAFS)混合料体系作为无熟料水泥，采用不同掺量的Na2CO3作为持久激发剂。还考察了添加不同比例的反应氧化镁(MgO)的效果。利用无侧限抗压强度、X射线衍射、热重分析、红外光谱和扫描电子显微镜对水泥浆体的力学、矿物学和微观结构进行了表征。结果表明，Na2CO3活化的FA/矿渣混合料的强度一般随时间和Na2CO3掺量的增加而提高。水化产物主要为低结晶度的C-(N)-A-S-H凝胶和类水滑石相。等温量热数据表明，在混合料中加入活性氧化镁对水化速率有明显的促进作用。此外，研究结果显示，在混合物中引入活性氧化镁后，浆体的强度和水化产物的化学成分发生了变化。(C)2015爱思唯尔有限公司。保留所有权利。
A system of alkali-activated fly ash (FA)/slag (AAFS) mixtures as a clinkerless cement was investigated with different dosages of Na2CO3, as a sustainable activator. The effect of incorporating various proportions of reactive magnesia (MgO) was also examined. Mechanical, mineralogical, and microstructural characterisation of the cement pastes was carried out using the unconfined compressive strength, X-ray diffraction, thermogravimetric analysis, infrared spectroscopy and scanning electron microscopy. It was found that the strength of Na2CO3 activated FA/slag mixtures generally increased with time and the Na2CO3 dosage. The hydration products were mainly C-(N)-A-S-H gel of low-crystallinity, which is rich in Al and may have included Na in its structure, and hydrotalcite-like phases. Adding reactive MgO in the mixes showed an accelerating effect on the hydration rate as suggested by the isothermal calorimetry data. Additionally, findings revealed variations on the strength of the pastes and the chemical compositions of the hydration products by introducing reactive MgO into the mixtures. (C) 2015 Elsevier Ltd. All rights reserved.