Effects of water-salt variation on physicomechanical properties of MgO-carbonated soil

Authors

• Yang Zhe, Yellow River Engineering Consulting Co ., Ltd., Zhengzhou , Henan 450003 , ChinaFollow
• Shi Zhixin, College of Civil Engineering , Nanjing Forestry University , Nanjing , Jiangsu 210037 , China
• Zhang Yuanyuan, Yellow River Engineering Consulting Co ., Ltd., Zhengzhou , Henan 450003 , China
• Cai Guanghua, College of Civil Engineering , Nanjing Forestry University , Nanjing , Jiangsu 210037 , China ;Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources , Changjiang River Scientific Research Institute , Wuhan , Hubei 430010 , ChinaFollow
• Qiu Jinwei, Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources , Changjiang River Scientific Research Institute , Wuhan , Hubei 430010 , China
• Li Ji, College of Civil Engineering , Nanjing Forestry University , Nanjing , Jiangsu 210037 , China

Corresponding Author

蔡光华，男，博士，副教授.E-mail：[email protected]

Abstract

To address the challenges associated with stabilizing saline soils and preventing salt-induced swelling upon exposure to water, silty soil containing sodium sulfate (Na2SO4) was treated using reactive MgO carbonation technology. With initial water content and Na2SO4 content as the main variables, the effects of water-salt coupling on carbonation curing effectiveness were systematically investigated through physicochemical characterization, mechanical testing, and microstructural analysis. For samples with initial water content levels of 25%, 27%, and 30%, the unconfined compressive strength exhibits distinct patterns within the Na2SO4 content range of 6%‒9%. Specifically, the strength of the 25% water content sample continues to increase with increasing Na2SO4 content. The 27% water content sample shows an initial increase followed by a decrease. The strength of the 30% water content sample consistently declines with increasing Na2SO4 content. Samples with lower initial water content demonstrate superior mechanical properties after carbonation curing. The dry density of all three groups of samples varies with Na2SO4 content. As Na2SO4 content increases, the dry density of samples with an initial water content of 25% first decreases, then increases, and finally decreases again, whereas that of samples with initial water content levels of 27% and 30% decreases continuously. XRD and SEM analyses reveal that as the initial water content increases, the characteristic diffraction peak intensities of the main carbonation products (nesquehonite, dypingite, and hydromagnesite ) significantly decrease. In the 30% water content sample, intense Mg (OH)2 diffraction peaks and characteristic peaks of mirabilite are detected, indicating that carbonation reactions are inhibited under high water content conditions, leading to a loose and porous soil microstructure with significantly weakened cementation between soil particles. This study elucidates the complex mechanisms underlying the effects of water-salt variation on the carbonation curing of silty soil using reactive MgO, providing key experimental parameters and a theoretical basis for the application of reactive MgO carbonation technology in the reinforcement of saline soils. The findings underscore the importance of strictly controlling initial water content and Na2SO4 content to achieve efficient reinforcement, ensure long-term service performance, and promote the sustainable utilization of saline soils.

Publication Date

10-29-2026

DOI

10.14048/j.issn.1671-2579.2026.05.006

First Page

53

Last Page

62

Submission Date

October 2026

Recommended Citation

Zhe, Yang; Zhixin, Shi; Yuanyuan, Zhang; Guanghua, Cai; Jinwei, Qiu; and Ji, Li (2026) "Effects of water-salt variation on physicomechanical properties of MgO-carbonated soil," Journal of China & Foreign Highway: Vol. 46: Iss. 5, Article 6.
DOI: 10.14048/j.issn.1671-2579.2026.05.006
Available at: https://zwgl1980.csust.edu.cn/journal/vol46/iss5/6

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