高掺量 MgO 碳化固化高含水率滩涂淤泥的胶结-损伤竞争机制研究

Cementation-Damage Competition Mechanism in High-Dosage MgO Carbonation and Stabilization of High-Water-Content Tidal Mud

摘要

针对高含水率滩涂淤泥难以快速硬化的工程难题，传统水泥固化技术因早期强度低而难以满足军事及应急场景下“小时级”快速构筑临时通路的严苛要求．为此，本研究聚焦高掺量活性 MgO 碳化固化的短期强度发展机制，通过无侧限抗压强度(UCS)试验，并结合 X 射线衍射(XRD)、热重(TG)分析、扫描电镜(SEM)与压汞法(MIP)等多尺度微观表征手段，系统揭示了 MgO 掺量、初始含水率与碳化时间对碳化产物演化及孔隙结构的耦合效应．结果表明：高初始含水率严重抑制 CO₂ 扩散，使碳化反应滞留于胶结能力较弱的水镁石阶段；而高掺量 MgO 可通过构建局部高反应势能区，有效补偿水分稀释效应，驱动水镁石持续转化为三水碳镁石等强胶结相，使试样在 2.0 h 内 UCS 突破 5 MPa，满足基本承载需求．然而，当 MgO 掺量超过 45%时，三水碳镁石晶体在受限孔隙内爆发式生长，产生显著结晶压力，引发微裂隙扩展与孔隙结构劣化，导致宏观强度不升反降．本文首次揭示并阐明了高掺量 MgO 碳化固化过程中的胶结-损伤竞争机制，并据此建立了融合物相含量、孔隙填充效率、含水率抑制因子与结晶损伤指数的多因素耦合强度模型，可以为滩涂地带快速构筑临时通路提供依据，并为 MgO 碳化固化掺量设计提供参考．

Abstract

The conventional cement-based stabilization is inadequate for rapidly hardening high-water-content tidal mud due to its low early strength and failure to meet the stringent“hour-scale”requirements for the rapid construction of temporary access routes in military and emergency scenarios. This study therefore investigates the short-term strength development mechanism of carbonation and stabilization using high dosages of reactive MgO. The uncon-fined compressive strength(UCS)tests coupled with multiscale microstructural characterization techniques，which include X-ray diffraction(XRD)，thermogravimetric(TG) analysis，scanning electron microscopy(SEM)，and mercury intrusion porosimetry(MIP)，systematically elucidate the coupled effects of MgO dosage，initial water content of the sample，and carbonation duration on the evolution of carbonation products and pore structure. The results show that high initial water content severely impedes CO₂ diffusion，arresting carbonation at the brucite stage with limited cementing capacity. By contrast，a high MgO dosage creates localized zones of elevated reaction potential，effectively counteracting the dilution effect of excess water and promoting the continuous conversion of brucite into strongly cementing phases such as nesquehonite. Consequently，the UCS exceeds 5 MPa within 2.0 h，meeting the minimum load-bearing requirement. However，when the MgO dosage exceeds 45%，explosive growth of nesque-honite crystals within confined pores generates substantial crystallization pressure，triggering microcrack propagation and pore structure degradation. This damage ultimately leads to a decrease，rather than an increase，in macroscopic strength. For the first time this study identifies and elucidates a cementation-damage competition mechanism governing high-dosage MgO carbonation and stabilization. Based on this mechanism，a multi-factor coupled strength model is developed that integrates phase content，pore-filling efficiency，a water-content inhibition factor，and a crystalli-zation-induced damage index. The proposed model provides a theoretical basis for the rapid deployment of temporary access routes on tidal flats and offers practical guidance for optimizing MgO dosage in carbonation and stabilization.

关键词

滩涂淤泥 / 高掺量 / 高含水率 / 碳化时间 / 物相演化 / 胶结结构 / 孔隙重构

Key words

tidal mud / high dosage / high water content / carbonation duration / phase evolution / cemented microstructure / pore structure reconfiguration

参考文献

[1] 王祥秋, 罗晓栋, 郑土永. 珠三角地区典型淤泥质土硬化土本构模型参数研究[J]. 中国港湾建设, 2024, 44(10): 44-50.

[2] Wang Xiangqiu, Luo Xiaodong, Zheng Tuyong. Study on constitutive model parameters of hardening soil for typical silt soil in the Pearl River Delta region[J]. China Harbour Engineering, 2024, 44(10): 44-50(in Chinese).

[3] 黄晓鹏. 加载方式对淤泥质土固结特性影响试验研究[J]. 北方建筑, 2025, 10(2): 123-126.

[4] Huang Xiaopeng. Experimental study on the influence of loading methods on consolidation characteristics of muddy soil[J]. Northern Building, 2025, 10(2): 123-126(in Chinese).

[5] 孙海超. 低水泥掺量淤泥固化土力学性能及微观结构特征研究[D]. 杭州：浙江大学， 2020.

[6] Sun Haichao. Study on Mechanical Properties and Microstructure Characteristics of Low Content Solidified Silt[D]. Hangzhou: Zhejiang University, 2020(in Chinese).

[7] 徐日庆, 朱坤垅, 黄 伟, 等. 淤泥质土固化及路用性能试验研究[J]. 湖南大学学报(自然科学版), 2022, 49(3): 167-174.

[8] Xu Riqing, Zhu Kunlong, Huang Wei, et al. Experimental study on solidification and road performance of mucky soil[J]. Journal of Hunan University(Natural Sciences), 2022, 49(3): 167-174(in Chinese).

[9] Sukmak P, de Silva P, Horpibulsuk S, et al. Sulfate resistance of clay-Portland cement and clay high-calcium fly ash geopolymer[J]. Journal of Materials in Civil Engineering, 2015, 27(5): 04014158.

[10] 谈云志,柯 睿， 陈君廉, 等. 偏高岭土增强石灰-水泥固化淤泥的耐久性研究[J]. 岩土力学, 2020, 41(4): 1146-1152.

[11] Tan Yunzhi, Ke Rui, Chen Junlian, et al. Enhancing durability of lime-cement solidified sludge with metakaolin[J]. Rock and Soil Mechanics, 2020, 41(4): 1146-1152(in Chinese).

[12] 郭 印. 淤泥质土的固化及力学特性的研究[D]. 杭州：浙江大学， 2007.

[13] Guo Yin. Study on Stabilization of Muddy Soil and Mechanical Properties of Stabilized Soil[D]. Hangzhou：Zhejiang University， 2007(in Chinese).

[14] 郑晨晖, 蔡光华, 钟煜清, 等. 碳化条件下电石渣-氧化镁固化淤泥土的试验研究[J]. 科技和产业, 2023, 23(9): 233-238.

[15] Zheng Chenhui, Cai Guanghua, Zhong Yuqing, et al. Experimental study of carbide slag-MgO stabilized mud under carbonation condition[J]. Science Technology and Industry, 2023, 23(9): 233-238(in Chinese).

[16] 曹伟达, 杨全兵. 碳化养护对钢渣-熟石灰固碳砖耐久性的影响[J]. 建筑材料学报, 2023, 26(3): 324-331.

[17] Cao Weida, Yang Quanbing. Effect of carbonation curing on durability of carbon fixing steel slag-slaked lime brick[J]. Journal of Building Materials, 2023, 26(3): 324-331(in Chinese).

[18] 蔡光华, 刘松玉, 曹菁菁. 活性氧化镁碳化加固粉土微观机理研究[J]. 土木工程学报, 2017, 50(5): 105-113, 128.

[19] Cai Guanghua, Liu Songyu, Cao Jingjing. Research on micro-mechanism of carbonated reactive MgO-stabilized silt[J]. China Civil Engineering Journal, 2017, 50(5): 105-113, 128(in Chinese).

[20] 刘松玉, 李 晨. 氧化镁活性对碳化固化效果影响研究[J]. 岩土工程学报, 2015, 37(1): 148-155.

[21] Liu Songyu, Li Chen. Influence of MgO activity on stabilization efficiency of carbonated mixing method[J]. Chinese Journal of Geotechnical Engineering, 2015, 37(1): 148-155(in Chinese).

[22] Yi Y L, Liska M, Unluer C, et al. Carbonating magnesia for soil stabilization[J]. Canadian Geotechnical Journal, 2013, 50(8): 899-905.

[23] 闵凡路, 申 政, 李彦澄, 等. 盾构淤泥质废弃黏土氧化镁固化-碳化试验及碳化机制研究[J]. 岩土力学, 2024, 45(2): 364-374.

[24] Min Fanlu, Shen Zheng, Li Yancheng, et al. Solidification and carbonization experimental study on magnesium oxide in shield waste soil and its carbonization mechanism[J]. Rock and Soil Mechanics, 2024, 45(2): 364-374(in Chinese).

[25] 刘松玉, 曹菁菁, 蔡光华. 活性氧化镁碳化固化粉质黏土微观机制[J]. 岩土力学, 2018, 39(5): 1543-1552, 1563.

[26] Liu Songyu, Cao Jingjing, Cai Guanghua. Microstructural mechanism of reactive magnesia carbonated and stabilized silty clays[J]. Rock and Soil Mechanics, 2018, 39(5): 1543-1552, 1563(in Chinese).

[27] 陈学军, 班如龙, 宋 宇, 等. 初始含水率对活性 MgO 碳化红黏土特性的影响[J]. 中国科技论文, 2022, 17(12): 1317-1324.

[28] Chen Xuejun, Ban Rulong, Song Yu, et al. Effect of initial water content on characteristics of reactive MgO carbonated red clay[J]. China Sciencepaper, 2022, 17(12): 1317-1324(in Chinese).

[29] 中国人民解放军总后勤部. GJB 3501-1998 军用道路工程技术标准[S]. 1998. General Logistics Department of the People's Liberation Army.

[30] GJB 3501-1998 Technical Standard of Military Road Engineering[S]. 1998(in Chinese).

[31] 中国人民解放军总后勤部. GJB 3364-1995 军用机场水泥混凝土道面使用质量评定标准[S]. 1995. General Logistics Department of the People's Liberation Army.

[32] GJB 3364-1995 Standard for Service Quality Evaluation of Cement Concrete Pavements in Military Airfields[S]. 1995(in Chinese).

[33] 中华人民共和国水利部. GB/T 50123-2019 土工试验方法标准[S]. 北京：中国计划出版社，2019. Ministry of Water Resources of the People's Republic of China.

[34] GB/T 50123-2019 Standard for Geotechnical Testing Method[S]. Beijing：China Planning Press，2019(in Chinese).

[35] 交通运输部公路科学研究院. JTG 3430-2020 公路土工试验规程[S]. 北京：人民交通出版社，2020. Research Institute of Highway，Ministry of Transport.

[36] JTG 3430-2020 Specifications for Highway Geotechnical Testing[S]. Beijing：China Communications Press，2020(in Chinese).

[37] 陈双影, 张旭良, 郭福水, 等. X 射线荧光光谱仪的介绍及应用[J]. 广东化工, 2024, 51(19): 195-196.

[38] Chen Shuangying, Zhang Xuliang, Guo Fushui, et al. Introduction and application of X-ray fluorescence spectrometer[J]. Guangdong Chemical Industry, 2024, 51(19): 195-196(in Chinese).

[39] 蔡光华, 刘松玉, 曹菁菁. 初始含水率对 MgO 碳化粉土强度和电阻率的影响[J]. 中国公路学报, 2017, 30(11): 18-26.

[40] Cai Guanghua, Liu Songyu, Cao Jingjing. Influence of initial water content on strength and electrical resistivity of MgO-carbonated silt[J]. China Journal of Highway and Transport, 2017, 30(11): 18-26(in Chinese).

[41] 曹菁菁. 活性氧化镁碳化固化土微观机制及应用研究[D]. 南京：东南大学， 2016.

[42] Cao Jingjing. The Application and Micro-Mechanism of Carbonated Reactive Magnesia Solidified Soils[D]. Nanjing：Southeast University， 2016(in Chinese).

[43] 王东星, 肖 杰, 李丽华, 等. 基于碳化-固化技术的武汉东湖淤泥耐久性演变微观机制[J]. 岩土力学, 2019, 40(8): 3045-3053.

[44] Wang Dongxing, Xiao Jie, Li Lihua, et al. Micro-mechanism of durability evolution of sludge dredged from East Lake, Wuhan based on carbonation-solidification technique[J]. Rock and Soil Mechanics, 2019, 40(8): 3045-3053(in Chinese).

[45] 李 听, 陈德平, 贾盼亚. 三水碳酸镁向水菱镁石转变的影响因素[C]// 第十届全国成矿理论与找矿方法学术讨论会论文摘要集. 西安，中国， 2023: 412-413.

[46] Li Ting, Chen Deping, Jia Panya. Factors influencing the transformation of nesquehonite to hydromagnesite [C]// Proceedings of the 10th National Symposium on Metallogenic Theory and Mineral Exploration Methods. Xi'an，China， 2023: 412-413(in Chinese).

[47] 孔祥辉, 梁允鹏, 崔 帅, 等. 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.

[48] Kong Xianghui, Liang Yunpeng, Cui Shuai, et al. Influencing factors and mechanism of dredged sediment carbonated and solidified with reactive MgO[J]. Journal of Building Materials, 2024, 27(7): 620-628(in Chinese).

[49] Unluer C, Al-Tabbaa A. Enhancing the carbonation of reactive MgO cement porous blocks through improved curing conditions[J]. Cement and Concrete Research, 2014, 59:55-65.

[50] Unluer C, Al-Tabbaa A. Characterization of light and heavy hydrated magnesium carbonates using thermal analysis[J]. Journal of Thermal Analysis and Calorimetry, 2014, 115(1): 595-607.

[51] Liska M. Performance of Reactive Magnesia Cement and Porous Construction Products[D]. Cambridge：University of Cambridge， 2009.

[52] 易耀林. 基于可持续发展的搅拌桩系列新技术与理论[D]. 南京：东南大学， 2013.

[53] Yi Yaolin. Sustainable Novel Deep Mixing Methods and Theory[D]. Nanjing：Southeast University， 2013(in Chinese).

[54] 吴 丹, 王玉琪, 武海虹, 等. 三水碳酸镁合成与形貌演变过程研究[J]. 人工晶体学报, 2014, 43(3): 606-613.

[55] Wu Dan, Wang Yuqi, Wu Haihong, et al. Research on preparation and morphology evolution of magnesium carbonate tri-hydrate[J]. Journal of Synthetic Crystals, 2014, 43(3): 606-613(in Chinese).

基金资助

国家自然科学基金资助项目(52578492)

江苏省基础研究专项基金资助项目(KYFYGKQTSZ25002)

陆军工程大学青年自主创新基金资助项目