Engineering Geology

Engineering Geology

Effect of magnesium chloride solution on the improvement of a clay soil

Authors
Soroush Mahdavian
Navid Rashidi
Ali Raeesi
Jamal Abdullahi
University of Tehran
10.22034/JEG.2025.19.1.1016071
Abstract
Clay soils typically have low strength and a high swelling percentage. They are considered as problematic soils in Civil Engineering projects. This research study examined the effects of magnesium chloride (MgCl2) solution on the clay soil improvement through conducting laboratory experiments. The experimental program included Atterberg limits, compaction, swelling, unconfined compression strength (UCS) and Scanning Electron Microscopy (SEM) tests. Available clay soil in the Lab was mixed with MgCl2 solution at weight percentages of 3%, 5%, 7% and 10% Samples for the swelling and strength tests were made using thestatic compaction method. The moisture and dry unit weight of the prepared samples were the same as those of thecorresponding compaction curves. The strength test results showed that the final strengths of the samples with 3% MgCl₂ at 7-, 14-, and 28-day curing times were 1401, 2018, and 1848 kPa, respectively. The results also showed that a reduction in strength of the samples occurred with more than a 3% solution of MgCl₂. For samples with 10% MgCl2 solution, the strength decreased until 14 days of curing time, but increased thereafter. Additionally, the results indicated that the reduction in swelling percentage compared to natural soil was 4.95%, 3.98%, 2.8%, and 3.9% for samples with 3%, 5%, 7%, and 10% MgCl₂, respectively, showing that the reduction in swelling depends on the MgCl₂ percentage. Additionally, the SEM results showed that the improvement in the soil was due to chemical reactions between the soil and MgCl₂.
Keywords
Clay soil
Magnesium chloride
Swelling
strength
curing time
SEM
Abu-Farsakh, M., Dhakal, S., & Chen, Q. (2015). Laboratory characterization of cementitiously treated/stabilized very weak subgrade soil under cyclic loading. Soils and Foundations, 55(3), 504-516.
Act, C. E. P. (2001). Priority substances list assessment report: Road salts. Environmental Canada, Quebec.
Ajayi, M. A., Grissom, W. A., Smith, L. S., & Jones, E. E. (1991). Epoxy–resin–based chemical stabilization of a fine, poorly graded soil system. Transportation Research Record, 1295, 95-108.
Ahmad, N., Hassan, F. U., & Belford, R. K. (2009). Effect of soil compaction in the sub-humid cropping environment in Pakistan on uptake of NPK and grain yield in wheat (Triticum aestivum): I. Compaction. Field Crops Research, 110(1), 54-60.
Attom, M. F., Al-Akhras, N. M., & Malkawi, A. I. (2009). Effect of fibers on the mechanical properties of clayey soil. Proceedings of the Institution of Civil Engineers-Geotechnical Engineering, 162(5), 277-282.
Bell, F. G. (1996). Lime stabilization of clay minerals and soils. Engineering geology, 42(4), 223-237.
Bolander, P. (1999). Laboratory testing of nontraditional additives for stabilization of roads and trail surfaces. Transportation research record, 1652(1), 24-31.
Deepak, M. S., Rohini, S., Harini, B. S., & Ananthi, G. B. G. (2021). Influence of fly-ash on the engineering characteristics of stabilised clay soil. Materials today: proceedings, 37, 2014-2018.
Etabragh, A.R., Babaei, M., Javadi, A.A. and Amini, M. (2024). Effects of two different polymers and calcium chloride solution on the swelling behavior of an expansive soil. Advances in Civil Materials. Vol.13, No.1, pp.1-15.
Estabragh, A. R., Beytolahpour, I., & Javadi, A. A. (2011a). Effect of resin on the strength of soil-cement mixture. Journal of Materials in Civil Engineering, 23(7), 969-976.
Estabragh, A. R., Bordbar, A. T., & Javadi, A. A. (2011b). Mechanical behavior of a clay soil reinforced with nylon fibers. Geotechnical and Geological Engineering, 29, 899-908.
Estabragh, A. R., Moghadas, M., & Javadi, A. A. (2013). Effect of different types of wetting fluids on the behaviour of expansive soil during wetting and drying. Soils and Foundations, 53(5), 617-627.
Estabragh, A. R., Khajepour, H., Javadi, A. A., & Amini, M. (2022). Effect of forced carbonation on the behaviour of a magnesia-stabilised clay soil. International Journal of Pavement Engineering, 23(5), 1691-1705.
Estabragh, A.R., Jahani, A., Javadi, A.A., Amini, M. and khajepour, H. (2025). Effect of different agents on the stabilization of a clay soil contaminated with glycerol. Geomechavics and Geoengineering. Vol.20, No.1, pp. 179-197.
Estabragh, A. R., Jandari, F., Javadi, A. A., & Amini, M. (2022). Effect of magnesia on stabilization of contaminated clay soil. ACI Materials Journal, 119 (3).
Estabragh, A. R., Babaei, M., Javadi, A. A., & Amini, M. (2024). Effects of two different polymers and calcium chloride solution on the swelling behavior of an expansive soil. Advances in Civil Engineering Materials, 13(1), 151-165.
Jianli, M., Youcai, Z., Jinmei, W., & Li, W. (2010). Effect of magnesium oxychloride cement on stabilization/solidification of sewage sludge. Construction and Building Materials, 24(1), 79-83.
Jin, F., Gu, K., & Al-Tabbaa, A. (2015). Strength and hydration properties of reactive MgO-activated ground granulated blastfurnace slag paste. Cement and Concrete Composites, 57, 8-16.
Latifi, N., Rashid, A. S. A., Siddiqua, S., & Horpibulsuk, S. (2015). Micro-structural analysis of strength development in low-and high swelling clays stabilized with magnesium chloride solution—A green soil stabilizer. Applied Clay Science, 118, 195-206.
Little, D. N., & Nair, S. (2009). Recommended practice for stabilization of subgrade soils and base materials.
McKeen, R. G. (1992). A model for predicting expansive soil behavior. In International conference on expansive soils (pp. 1-6).
Mitchell, J. K., & Soga, K. (2005). Fundamentals of soil behavior.
Morin, D., & Perchanok, M. (2000). Road salt loadings in Canada.
Namdaraligoudarz, P. A., Estabragh, A. R., Abdullahi, J. A., (2010). Improvement of clay soils using mechanical and chemical methods. Paper presented at the 6th National Civil Engineering Congress in Semnan. (in persian)
Puppala, A. J., Mohammad, L. N., & Allen, A. (1999). Permanent deformation characterization of subgrade soils from RLT test. Journal of Materials in Civil Engineering, 11(4), 274-282.
Sherwood, P. (1993). Soil stabilization with cement and lime.
Tang, X. Y., Zhu, Y. G., Shan, X. Q., McLaren, R., & Duan, J. (2007). The ageing effect on the bioaccessibility and fractionation of arsenic in soils from China. Chemosphere, 66(7), 1183-1190.
Tremblay, H., Duchesne, J., Locat, J., & Leroueil, S. (2002). Influence of the nature of organic compounds on fine soil stabilization with cement. Canadian geotechnical journal, 39(3), 535-546.
Turkoz, M., Savas, H., Acaz, A., & Tosun, H. (2014). The effect of magnesium chloride solution on the engineering properties of clay soil with expansive and dispersive characteristics. Applied Clay Science, 101, 1-9.
Yi, Y., Liska, M., & Al-Tabbaa, A. (2014). Properties of two model soils stabilized with different blends and contents of GGBS, MgO, lime, and PC. Journal of Materials in Civil Engineering, 26(2), 267-274.