活性MgO碳化固化疏浚底泥的影响因素及作用机理
作者:
作者单位:

1.山东建筑大学 交通工程学院,山东 济南 250101;2.山东易方达建设管理集团有限公司, 山东 济南 250014

作者简介:

孔祥辉(1978—),男,山东青岛人,山东建筑大学副教授,硕士生导师,博士.E-mail:kongxh@sdjzu.edu.cn

通讯作者:

张思峰(1976—),男,山东济宁人,山东建筑大学教授,硕士生导师,博士.E-mail:sddxzsf@163.com

中图分类号:

U416.1

基金项目:

山东省重点研发计划项目(重大科技创新工程)(2020CXGC011404)


Influencing Factors and Mechanism of Dredged Sediment Carbonated and Solidified with Reactive MgO
Author:
Affiliation:

1.School of Transportation Engineering, Shandong Jianzhu University, Jinan 250101, China;2.Shandong Yifangda Construction Management Group Co., Ltd., Jinan 250014, China

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    摘要:

    采用MgO碳化技术对疏浚底泥进行固化处理,通过强度试验和微观特性试验,系统分析了活性MgO碳化固化底泥的主要影响因素及微观机理.结果表明:增加活性MgO掺量能生成较多的水化产物和碳化产物,使得底泥强度明显增大;土体含水率与压实度能够影响CO2在土体内部的运移,二者增大导致CO2吸附量减少,从而影响底泥的碳化固化效果;长时间的碳化作用导致部分碳化产物发生变质反应,底泥强度随碳化时间的延长呈先增后减趋势;水化产物和碳化产物对土颗粒的包裹、胶结和孔隙填充是活性MgO碳化固化底泥的主要作用机理.

    Abstract:

    MgO carbonization technology was used to solidify the dredged sediment. The main influencing factors and micro-mechanism of reactive MgO carbonization solidification of sediment were systematically analyzed through strength tests and microscopic characteristic tests. The results indicate that more hydration products and carbonization products can be generated with the increase of reactive MgO content, and the strength of sediment increases significantly. The water content and compaction degree are two main factors that affect the transport of CO2 in soil, and the increase of both will lead to the decrease of CO2 absorption, thus affecting the carbonization and solidification effect of sediment. The long-term carbonization can cause some carbonization products to undergo metamorphic reaction, so the strength of sediment increases first and then decreases with the increase of carbonization time. The encapsulation, cementation and pore filling of soil particles by hydration products and carbonization products are the main mechanism of reactive MgO carbonization solidification of sediment.

    表 2 活性MgO的化学组成Table 2 Chemical composition(by mass) of reactive MgO
    表 3 碳化固化试验方案Table 3 Carbonization solidification test scheme
    表 1 疏浚底泥的基本物理力学性能Table 1 Basic physical and mechanical properties of dredged sediment
    图1 疏浚底泥颗粒级配曲线Fig.1 Particle gradation curve of dredged sediment
    图2 碳化釜示意图Fig.2 Schematic diagram of carbonization kettle
    图3 总体试验流程图Fig.3 Overall test flow chart
    图4 活性MgO掺量对试件无侧压抗压强度和CO2吸附能力的影响Fig.4 Effect of reactive MgO content on unconfined compression strength and CO2 absorption capacity of specimens
    图5 土体含水率对试件无侧限抗压强度与CO2吸附能力的影响Fig.5 Effect of soil water content on unconfined compression strength and CO2 absorption capacity of specimens
    图6 土体压实度对试件无侧限抗压强度与CO2吸附能力的影响Fig.6 Effect of compaction degree on unconfined compression strength and CO2 absorption capacity of specimens
    图7 碳化时间对试件无侧限抗压强度与CO2吸附能力的影响Fig.7 Effect of carbonization time on unconfined compression strength and CO2 absorption capacity of specimens
    图8 各试样的XRD图谱Fig.8 XRD patterns of samples
    图9 未碳化和碳化底泥的EDS能谱分析Fig.9 EDS spectrum analyses of uncarbonated and carbonated sediment
    图10 天然疏浚底泥、未碳化和碳化底泥的SEM照片Fig.10 SEM images of natural dredged sediment, uncarbonated and carbonated sediment
    图11 天然疏浚底泥、未碳化和碳化底泥的压汞试验结果Fig.11 MIP test results of natural dredged sediment, uncarbonated and carbonated sediment
    图12 MgO碳化固化微观机制模型Fig.12 Micro-mechanism model of MgO carbonization and solidification
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引用本文

孔祥辉,梁允鹏,崔帅,王潇康,张思峰.活性MgO碳化固化疏浚底泥的影响因素及作用机理[J].建筑材料学报,2024,27(7):620-628

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  • 收稿日期:2023-09-03
  • 最后修改日期:2024-02-03
  • 在线发布日期: 2024-08-09
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