Document Type : Original Article


Civil Engineering Department, University of Technology, 10066, Baghdad, Iraq



Soft clay soil is one of the problematic soil which is widespread in Iraq especially in middle and south of Iraq and has a low bearing capacity. This study investigates some of the mechanical properties of soft clay soil after adding the environmental waste material, egg shells. This study compares eggshell ash (ESA), eggshell powder (ESP), and limestone (L), which can be used as a stabilizer for soft clay while preserving natural limestone from consumption. ESP can be used as a replacement for limestone due to some similarities in chemical composition between it and limestone components. Soft clay soil brought from southern Iraq, which is used for this study and mixed with different percentages of ESA (2 - 6%), ESP (4 - 20%), and L (4 - 24%) by dry weight of soil. Lab tests such as specific gravity, Atterberg limits, compaction, and triaxial tests were used to evaluate the amendment samples and compare them with the reference one. The experimental results indicated that ESA increased the qualities of consistency, strength, and plasticity. It was found that the activity of the natural soil without any additives was decreased from 0.60 to 0.20 at 6% of ESA, while the activity dropped to 0.23 at 20% of ESP and 0.25 at 30% of L. Thus, it can be concluded that ESA was an effective stabilizer for improving the mechanical properties of soft soil samples.


  1. Abbas, J. M., Ibrahim, A. M., & Shihab, A. M. (2020). Investigation to some preliminary geotechnical properties of soft clay stabilized by fly ash-based geopolymers. . Key Engineering Materials, 857, 283-291.

    Abdulrahman, S. M., & Ihsan, E. A. A.-A. (2020). Influences of Eggshell Powder to reduce the collapse of soil gypsum. IOP Conference Series: Materials Science and Engineering, 745(1), 012135. doi:10.1088/1757-899X/745/1/012135

    Ahmed, A., & Issa, U. H. (2014). Stability of soft clay soil stabilised with recycled gypsum in a wet environment. Soils and Foundations, 54(3), 405-416. doi:10.1016/j.sandf.2014.04.009

    Arulrajah, A., Piratheepan, J., Disfani, M. M., & Bo, M. W. (2013). Geotechnical and Geoenvironmental Properties of Recycled Construction and Demolition Materials in Pavement Subbase Applications. Journal of Materials in Civil Engineering, 25(8), 1077-1088. doi:10.1061/(asce)mt.1943-5533.0000652

    Astbury, N. F., Moore, F., & Lockett, J. A. (1966). A cyclic torsion test for study of plasticity. Trans. Br. Ceram. Soc., 65, 435-461.

    Bhavsar, A. P., & Joshi, H. (2014). Effect of burnt brick dust on engineering properties on expansive soil. Int. J. Renew. Energy Technol., 3, 433-441.

    Blayi, R. A., Sherwani, A. F. H., Ibrahim, H. H., Faraj, R. H., & Daraei, A. (2020). Strength improvement of expansive soil by utilizing waste glass powder. Case Studies in Construction Materials, 13. doi:10.1016/j.cscm.2020.e00427

    Brownell, & W.E. (1977). Structural clay products. Applied Mineralogy, 9, Springer, Berlin. .

    Huang, W., Wen, K., Liu, D., Dong, Q., Li, J., Li, Y., & Li, L. (2020). Experimental study on influence of excess pore water pressure and unloading ratio on unloading mechanical properties of marine sedimentary soft soils. Ocean Eng., 195.

    Ibrahim, O. A., Çabalar, A. F., & Abdulnafaa, M. D. (2018). Improving Some Geotechnical Properties of an Organic Soil Using Crushed Waste Concrete. The International Journal of Energy & Engineering Sciences, 3(3), 100-112.

    Indraratna, B., Chu, J., & Cholachat, R. (2015). Embankments with Special Reference to Consolidation and Other Physical Methods. Ground Improvement Case Histories. Amsterdam, The Netherlands: Elsevier.

    Islam, A., Dwivedi, V. K., & Dwivedi, S. P. (2021). Effect of Friction Stir Process Parameters on Mechanical Properties of Al/Eggshell/SiC Composite Material. International Information and Engineering Technology Association, 45(1), 51-57. doi:

    1. O. Afolayan, J. O., F. O. P. Oriola, F. O. P., G. Moses, G., & Sani, J. E. (2017). Investigating the effect of eggshell ash on the properties of sandcrete block. International Journal of Civil Engineering, Construction and Estate Management, 5(3), 43-54.

    Karkush, M. O., & Yassin, S. (2019). Improvement of Geotechnical Properties of Cohesive Soil Using Crushed Concrete. Civil Engineering Journal, 5(10), 2110-2119. doi:10.28991/cej-2019-03091397

    Moore, F. (1965). Rheology of Ceramic Systems. London: McLaren and Sons.

    Mtallib, M. O. A., & Rabiu, A. (2009). Effects of Egg Shells Ash on The Setting Time of Cement. Journal of Technology    University of Nigeria Nsukka,, 28(2), 29-38.

    Nicholson, P. G. (2015). Soil improvement and ground modification methods. The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK225 Wyman Street, Waltham, MA 02451, USA: Elsevier.

    Norton, F. H. (1983). An instrument for measuring the workability of clays. J. Am. Ceram. Soc., 21, 33-36.

    Okonkwo, U. N., Odiong, & Akpabio. (2012). The effects of eggshell of eggshell Ash on strength properties of cement-stabilized lateritic. International Journal of Sustainable Construction Engineering & Technology, 3(1), 2180-3242.

    Pastor, J., Tomás, R., Cano, M., Riquelme, A., & Gutiérrez, E. (2019). Evaluation of the Improvement Effect of Limestone Powder Waste in the Stabilization of Swelling Clayey Soil. Sustainability, 11(3). doi:10.3390/su11030679

    Perkins, W. W. (1995). Ceramic Glossary. Westerville, OH., USA: The American Ceramic Society.

    Pliya, P., & Cree, D. (2015). Limestone derived eggshell powder as a replacement in Portland cement mortar. Construction and Building Materials, 95, 1-9.

    Sathiparan, N. (2021). Utilization prospects of eggshell powder in sustainable construction material–A review. Construction and Building Materials, 293(123456). doi:

    Singer, F., & Singer, S. S. (1979). Industrial Ceramics. London: Chapman & Hall.

    Tiong, H. Y., Lim, S. K., Lee, Y. L., Ong, C. F., & Yew, M. K. (2020). Environmental impact and quality assessment of using eggshell powder incorporated in lightweight foamed concrete. Construction and Building Materials, 244, 118341. doi:

    Wei, Z., Xu, C., & Li, B. (2009). Application of waste eggshell as low-cost solid catalyst for biodiesel production. Bioresource Technology, 100(11), 2883-2885. doi:

    Yie, L. S. (2019). Undrained Shear Strength of Soft Clay Stabilised with Eggshell Ash and Silica Fume. (B.Sc.), University Malaysia Pahang,