A parametric study of accelerated carbonation in alkali-activated slag
A parametric study of accelerated carbonation in alkali-activated slag
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DOI：
10.1016/j.cemconres.2021.106454
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发表时间：
2021-04-14
影响因子：
11.4
通讯作者：
White, Claire E.
中科院分区：
文献类型：
--
作者：
McCaslin, Eric R.;White, Claire E.
抗碳化性是低二氧化碳水泥替代品必须具备的一个重要特性，对于承受高浓度二氧化碳的水泥替代品（如用于油井建设和地下碳封存的水泥替代品）来说，这一点尤为重要。本文利用x射线衍射（XRD）和傅里叶变换红外（FTIR）光谱对侵蚀环境下碱活化渣（AAS）碳化进行了参数化研究，以检验(i)碳酸钙的多态性，（ii）用热重分析（TGA）分析碳酸钙的形成和二氧化碳的吸附程度。通过改变炉渣的镁含量、活化剂类型（氢氧化钠和硅酸钠）、活化剂浓度和碳化前的固化时间，研究了一系列的AASs。研究发现，(i)来自炉渣的镁和（ii）来自活化溶液的二氧化硅都是降低含钠钙-铝-硅酸盐水合物凝胶脱钙倾向的必要条件。
Resistance to carbonation is one important attribute that low-CO2 cement alternatives must possess, and is particularly crucial for cement alternatives subjected to aggressive CO2 concentrations such as those used in construction of oil wells and wells for below ground carbon sequestration. Here, a parametric study of alkali-activated slag (AAS) carbonation in aggressive environments has been conducted to examine (i) calcium carbonate polymorphism using X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy, and (ii) the extent of calcium carbonate formation and CO2 adsorption using thermogravimetric analysis (TGA). A range of AASs have been studied by varying the magnesium content of the slag, the activator type (sodium hydroxide and sodium silicate), the activator concentration, and the curing time prior to carbonation. It was uncovered that both (i) magnesium from the slag and (ii) silica from the activating solution are needed to reduce the propensity for the sodium-containing calcium-alumino-silicate-hydrate gel to undergo decalcification.