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田    洋

（ 中国铁建港航局集团有限公司总承包分公司 ，广东 珠海 519000)

摘    要 ：CO₂ 碳化－水泥水化协同固化土是兼具固化增强和 CO₂ 永久封存双重效能的新颖技术。然而，碳化水泥固化土宏微观特征与耐侵蚀性的研究，目前明显偏少 。通过抗压强度 、扫描电镜 、X 射线衍射和硫酸盐侵蚀试验 ，深入评价 CO₂ 碳化－水泥协同固化土抗压强度 、微观机制与耐侵蚀性 。结果表明 ：水分软化作用引起湿水养护碳化试样抗压强度低于标准养护试样 ，二者高低与标准养护时间 、碳化时间及施作顺序紧密相关 ；CO₂ 碳化反应消耗水泥固化体系内部水化产物，生成细长棒状霰石和立方体状方解石，密集堆积于粒间孔隙和颗粒表 面进而提高试样密实度与抗压强度 ；硫酸钠溶液浸泡试样整体完整性良好，仅局部有少量土粒脱落 ，水泥固化土抵抗硫酸盐侵蚀能力依次为 B - 7d>7d- C - 1d>C- 3d;  三种试样抗压强度随浸泡时间变化规律基本一致 ， 即抗压强度先快速下降 ，之后逐渐回升并有持续增长趋势。

关键词 ：CO2 碳化 ；水泥水化 ；强度 ；微观结构 ；耐侵蚀性

       中图分类号 ：TU447           

文献标志码 ：A            

文章编号 ：1005- 8249  (2023)   06- 0110- 06

DOI : 10. 19860/j . cnki . issn1005- 8249. 2023 . 06. 018

TIAN Yang

( General Contracting Company ,   CRCC  Harbour & Channel Engineering Bureau Group ,  Zhuhai 519000 ,   China)

Abstract: The combined soil solidification based on CO2 carbonation-cement hydration is a novel technology to realize the strength enhancement and permanent storage of CO2. However, there is quite little research on the macro- and micro- characteristics and erosion resistance of carbonated solidified soil. Through compressive strength, scanning electron microscope, X-ray diffraction and sulfate erosion tests, the strength, mechanism and erosion resistance of CO2 carbonated solidified soil were deeply evaluated. The results show that the compressive strength of carbonated samples cured in water is lower than that of standard samples due to the water softening effect, and their magnitude is closely related to curing time, carbonation time and their sequence. CO2 carbonation consumes cement hydration products to produce slender rod aragonite and cubic calcite, which are densely stacked in intergranular pores and particle surfaces, improving the compressive strength and compactness of sample. After being soaked in sulfate solution, the overall integrity of samples is still excellent, and only a small amount of soil particles fall off locally. The resistance of cement solidified soil to sulphate attack follows the order: B-7>7d-c-1d>c-3d. The change of compressive strength of samples with soaking time is nearly the same, i.e. the strength decreases rapidly at first, and then rises gradually, followed by a continuous growth trend.

Keywords: CO₂ carbonation; cement hydration; strength; microstructure; resistance to erosion

作者简介： 田洋  (1973—) ,  男 ，学士 ，工程师／经济师 。主 要研究方向 ：工程技术研发与项目施工管理。

收稿日期 ：2023- 05- 14