Abstract While CO2-resistant cement materials are crucial in oil and gas industries, the CO2 emissions associated with manufacturing oil-well cements have necessitated the development of lower-CO2 alternatives with enhanced carbonation resistance. A higher magnesium content blast furnace slag precursor for alkali-activated slag (AAS) has been shown to increase resistance to accelerated carbonation-induced degradation. This investigation assesses the effects of sample age, AAS magnesium content, and carbonation (exposure to 100% CO2) on the multiscale pore structure of AASs (nanometers to microns). The pore size distributions and diffusion tortuosities of ordinary Portland cement (OPC) and silicate-activated slag pastes are obtained through the techniques of nitrogen sorption, mercury intrusion porosimetry, and X-ray microtomography. These pore morphology properties show AAS to be more resistant to pore structural degradation following accelerated carbonation than OPC, and increased magnesium content in AAS is shown to improve its resistance to gel decalcification and capillary pore formation during carbonation.

中文翻译：

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镁含量和碳化对碱活化渣多尺度孔隙结构的影响

摘要 虽然抗 CO2 水泥材料在石油和天然气工业中至关重要，但与制造油井水泥相关的 CO2 排放使得开发具有增强抗碳化能力的低 CO2 替代品成为必要。用于碱活化炉渣 (AAS) 的高镁含量高炉炉渣前体已被证明可提高对加速碳化诱导降解的抵抗力。本研究评估了样品年龄、AAS 镁含量和碳化（暴露于 100% CO2）对 AAS 多尺度孔隙结构（纳米到微米）的影响。普通硅酸盐水泥（OPC）和硅酸盐活化矿渣浆的孔径分布和扩散曲折度是通过氮吸附、压汞孔隙率和X射线显微断层扫描技术获得的。