Carbonation of magnesium oxysulfate cement and its influence on mechanical performance
Carbonation of magnesium oxysulfate cement and its influence on mechanical performance
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硫氧镁水泥的碳化及其对力学性能的影响
DOI：
10.1016/j.conbuildmat.2019.07.341
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发表时间：
2019-10-30
影响因子：
7.4
通讯作者：
Liu, Junzhe
中科院分区：
文献类型：
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作者：
Ba, Mingfang;Xue, Tao;Liu, Junzhe
为了在土木工程中推广硫氧镁（MOS）水泥，有必要研究其碳化相关的耐久性。研究发现，碳化可以在一定程度上提高MOS水泥的抗压和抗折强度，并且在碳化过程中，MOS水泥的抗压强度先逐渐增加，然后降低。碳酸化28天硬化MOS水泥浆体的极限压缩力位移比同龄期未碳酸化的要大。采用蒸发水测试和X射线计算机断层扫描（X-CT）来检查碳化和未碳化的MOS水泥浆体的多孔结构。研究发现，碳化使水灰比为0.5的硬化MOS水泥的中孔（≥38μm）体积比细化了约17%。采用X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）分析MOS水泥的碳化特性。结果表明，氢氧化镁和一些碱性硫酸镁相明显被二氧化碳中和，在硬化的MOS水泥中形成碳酸镁相，从而导致细化的多孔结构和相应增加的韧性。 (C) 2019 Elsevier Ltd. 保留所有权利。
In order to popularize magnesium oxysulfate (MOS) cement in civil engineering, it is very necessary to investigate its carbonation related durability. It was found that carbonization can increase compressive and flexural strength of MOS cement to some extent and compressive strength of MOS cement increases gradually at first, then decreases during carbonation process. The displacement to ultimate compressive force of hardened MOS cement paste carbonated for 28 days is larger than that of non-carbonated one at the same age. Evaporable water testing and X-ray computed tomography (X-CT) were adopted to examine the porous structure of MOS cement paste with and without carbonation. It was found that carbonation refines the meso-pore (>= 38 mu m meters) volume ratio of hardened MOS cement with 0.5 water-to-cement ratio by about 17%. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were adopted to analyze the carbonation characteristics of MOS cement. The results indicate that magnesium hydroxide and some basic magnesium oxysulfate phase are obviously neutralized with carbon dioxide to form magnesium carbonate phases in the hardened MOS cement, which leads to the refined porous structures and corresponding increased toughness. (C) 2019 Elsevier Ltd. All rights reserved.