Vol. 15 No. 02 (2025): Journal of Materials & Construction
##common.pageHeaderLogo.altText##
JOURNAL OF MATERIALS & CONSTRUCTION

ISSN: 2734-9438

Website: www.jomc.vn

Delayed-Expansion MgO in mass concrete for Thermal-Stress control in arch dams: A comprehensive review and roadmap for Vietnam

Nguyen Van Chinh , Tieu Xuan Hoang , Chu Viet Thuc , Le Thai Binh

Keywords:

MgO expansive agent
Arch dam
Mass concrete
Delayed expansion
Thermal cracking
Autogenous volume deformation

Abstract

Temperature cracking poses a major challenge in arch dams and other massive concrete structures. During cement hydration, heat accumulation followed by cooling creates tensile stresses that may exceed the material’s tensile strength, leading to cracking and structural weakening. For arch dams, where compressive integrity is essential to transfer loads to abutments, even small thermal cracks can endanger global stability. Magnesium oxide (MgO) has been proven over decades to be an effective internal expansive agent for controlling thermal stress in mass concrete. Its delayed hydration to magnesium hydroxide [Mg(OH)₂] generates gradual expansion that compensates for thermal contraction during cooling. This review summarizes mechanisms, laboratory results, field experiences, and modeling of MgO expansion, emphasizing its application in arch dams. Studies from projects such as Baishan, Qingxi, and Three Gorges show that 3-6% MgO can reduce peak thermal stress by up to 40% and crack density by about 50%. Microstructural analyses confirm a denser matrix and improved durability, while numerical models indicate lower tensile stress and higher stability. For Vietnam’s hydropower projects, this paper proposes applying MgO-based temperature-stress control through optimized dosage, particle-size refinement, and long-term validation to develop future TCVN standards for mass concrete in arch dams.

User Navigation

PDF

How to Cite

Nguyen Van Chinh, Tieu Xuan Hoang, Chu Viet Thuc, & Le Thai Binh. (2025). Delayed-Expansion MgO in mass concrete for Thermal-Stress control in arch dams: A comprehensive review and roadmap for Vietnam. JOURNAL OF MATERIALS & CONSTRUCTION, 15(02), Page 80 – Page 89. https://doi.org/10.54772/jomc.v15i02.1156

References

  1. L. Mo, M. Deng, and A. Wang, “Effects of MgO-based expansive additive on compensating the shrinkage of cement paste under non-wet curing conditions,” vol. 34, pp. 377–383, 2012, doi: 10.1016/j.cemconcomp.2011.11.018.
  2. L. Mo, M. Deng, M. Tang, and A. Al-Tabbaa, “MgO expansive cement and concrete in China: Past, present and future [J],” Cem. Concr. Res., vol. 57, pp. 1–12, 2014, [Online]. Available: http://dx.doi.org/10.1016/j.cemconres.2013.12.007
  3. L. Wang, H. Q. Yang, S. H. Zhou, E. Chen, and S. W. Tang, “Mechanical properties, long-term hydration heat, shinkage behavior and crack resistance of dam concrete designed with low heat Portland (LHP) cement and fly ash,” Constr. Build. Mater., vol. 187, pp. 1073–1091, 2018, doi: https://doi.org/10.1016/j.conbuildmat.2018.08.056.
  4. M. Van Tran, V. N. Chau, and P. H. Nguyen, “Prediction and control of temperature rise of massive reinforced concrete transfer slab with embedded cooling pipe,” Case Stud. Constr. Mater., vol. 18, p. e01817, 2023, doi: https://doi.org/10.1016/j.cscm.2022.e01817.
  5. V. C. Nguyen, F. G. Tong, V. N. Nguyen, C. Liu, D. T. Phan, and G. Liu, “A Study on Temperature Stress Control Measures of MgO Concrete Dam,” Int. J. Eng. Res. Technol., vol. 9, no. 06, pp. 1401–1407, 2020.
  6. S. Li, Y. Feng, and J. Yang, “Expansion Mechanism and Properties of Magnesium Oxide Expansive Hydraulic Cement for Engineering Applications,” Adv. Mater. Sci. Eng., vol. 2021, pp. 11–14, 2021, doi: 10.1155/2021/5542072.
  7. B. F. Zhu, “On Construction of Dams by Concrete With Gentle Volume Expansion [J],” J. Hydroelectr. Eng., no. 3, pp. 1–13, 2000.
  8. V. C. Nguyen, F. G. Tong, and V. N. Nguyen, “Modeling of autogenous volume deformation process of RCC mixed with MgO based on concrete expansion experiment,” Constr. Build. Mater., vol. 210, pp. 650–659, 2019, doi: https://doi.org/10.1016/j.conbuildmat.2019.03.226.
  9. M. Li, A. Su, H. Li, Y. Wang, and Q. Tian, “Effect of expansive agent on temperature and deformation of concrete under simulated actual construction condition,” Case Stud. Constr. Mater., vol. 22, p. e04178, 2025, doi: https://doi.org/10.1016/j.cscm.2024.e04178.
  10. L. Wang et al., “Influence of reactivity and dosage of MgO expansive agent on shrinkage and crack resistance of face slab concrete,” Cem. Concr. Compos., vol. 126, p. 104333, 2022, doi: https://doi.org/10.1016/j.cemconcomp.2021.104333.
  11. L. Mo, M. Deng, and M. Tang, “Effects of calcination condition on expansion property of MgO-type expansive agent used in cement-based materials,” Cem. Concr. Res., vol. 40, no. 3, pp. 437–446, 2010, doi: https://doi.org/10.1016/j.cemconres.2009.09.025.
  12. F. Cao, M. Miao, and P. Yan, “Hydration characteristics and expansive mechanism of MgO expansive agents,” Constr. Build. Mater., vol. 183, pp. 234–242, 2018, doi: https://doi.org/10.1016/j.conbuildmat.2018.06.164.
  13. S. Rawat, J. Vongsvivut, L. Zhang, and Y. X. Zhang, “Mechanical performance and microstructure evolution of MgO-doped high volume GGBFS-based engineered cementitious composites at room and elevated temperatures,” J. Build. Eng., vol. 98, p. 111437, 2024, doi: https://doi.org/10.1016/j.jobe.2024.111437.
  14. Y. Ye et al., “Effect of nano-magnesium oxide on the expansion performance and hydration process of cement-based materials,” Materials (Basel)., vol. 14, no. 13, pp. 1–14, 2021, doi: 10.3390/ma14133766.
  15. Y. Chen et al., “Effect of nano-MgO on basic properties and microstructures of cement-based materials,” Emerg. Mater. Res., vol. 11, no. 3, pp. 376–387, 2022, doi: https://doi.org/10.1680/jemmr.22.00033.
  16. J. Zhang, T. Lv, Q. Han, Y. Zhu, D. Hou, and B. Dong, “Effects of fly ash on MgO-based shrinkage-compensating cement: Microstructure and properties,” Constr. Build. Mater., vol. 339, p. 127648, 2022, doi: https://doi.org/10.1016/j.conbuildmat.2022.127648.
  17. C. Feng, C. Zhao, X. Yu, J. Xiong, and L. Tang, “A mathematical model of the expansion evolution of magnesium oxide in mass concrete based on hydration characteristics,” Materials (Basel)., vol. 14, no. 12, pp. 0–16, 2021, doi: 10.3390/ma14123162.
  18. J. Lu, P. Feng, L. Shao, and H. Li, “The effect of internal relative humidity on the early age deformation of cement paste containing magnesia,” Constr. Build. Mater., vol. 283, p. 122604, 2021, doi: https://doi.org/10.1016/j.conbuildmat.2021.122604.
  19. F. Jiang, Z. Mao, and L. Yu, “Hydration and Expansion Characteristics of MgO Expansive Agent in Mass Concrete,” Materials (Basel)., vol. 15, no. 22, 2022, doi: 10.3390/ma15228028.
  20. X. Zhou, Z. Mao, P. Luo, and M. Deng, “Effect of Mineral Admixtures on the Mechanical and Shrinkage Performance of MgO Concrete,” Materials (Basel)., vol. 16, no. 9, 2023, doi: 10.3390/ma16093448.
  21. H. Su, J. Li, and Z. Wen, “Evaluation of Various Temperature Control Schemes for Crack Prevention in RCC Arch Dams During Construction,” Arab. J. Sci. Eng., vol. 39, no. 5, pp. 3559–3569, 2014, doi: 10.1007/s13369-014-1010-1.
  22. Z. S. Cao, “Crack prevention technique in rapid dam construction with MgO weakly expending concrete [J],” Water Power, no. 6, pp. 52–53, 1994.
  23. C. Lyu, C. Yu, C. Lu, L. Pan, W. Li, and J. Liu, “Long-Term Performance and Microstructural Characterization of Dam Concrete in the Three Gorges Project,” Engineering, vol. 33, pp. 237–262, 2024, doi: 10.1016/j.eng.2023.04.017.
  24. Y. Qing, C. Huxing, W. Yuqing, W. Shangxian, and L. Zonghan, “Effect of MgO and gypsum content on long-term expansion of low heat Portland slag cement with slight expansion,” Cem. Concr. Compos., vol. 26, no. 4, pp. 331–337, 2004, doi: https://doi.org/10.1016/S0958-9465(02)00145-2.
  25. C. J. Du, “A Review of Magnesium Oxide in Concrete,” Concr. Int., vol. 27, pp. 45–50, 2005.