Effects of Silica Fume and Nano-silica on the Engineering Properties of Kaolinite Clay

Document Type : Research Article


1 School of Civil Engineering, Iran University of Science and Technology, Tehran, Iran

2 School of Civil Engineering, Alaodoleh Semnani Institute of Higher Education, Garmsar, Iran

3 Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran


The improvement of geotechnical properties of weak soils is of interest through the resources shortage. Therefore, this study focused on the effect of silica fume as industrial waste products and nano-silica on geotechnical characteristics and micro-structural properties of kaolinite clay as a soft soil with poor strength properties. Silica fume was added to the kaolinite clay to enhance the strength with 5, 10 and 15%. Moreover stabilized soil with nano-silica were fabricated with 1, 2 and 3% by dry weight of the soil. Then, Atterberg limits, standard proctor, unconfined compressive strength, and California bearing ratio tests were conducted. In addition, the micro-structural changes of soil samples through the stabilization were examined using scanning electron microscope. The results indicated that silica fume and nano-silica increase the optimum water content and decrease the maximum dry density of the stabilized soils. Addition of 15% silica fume and 3% nano-silica to kaolinite clay improved the unconfined compressive strength at curing age of 28 days by up to 70% and 55%, respectively. Also, the results of soaked California bearing ratio test after 7 days of curing demonstrated that 15% of silica fume and 3% nano-silica increased the California bearing ratio values about two times more than the raw soil. Scanning electron microscope (SEM) images were then utilized to evaluate the effects of additives on the kaolinite clay soil. It was concluded that silica fume and nano-silica filled pore space between clay particles and a dense matrix were formed. This textural event caused an improvement in compressive strength of stabilized soils.


Main Subjects

[1] R.L. Parsons, C.P. Johnson, S.A. Cross, Evaluation of soil modification mixing procedures, Kansas Department of Transportation, 2001.
[2] INDOT, Design procedure for soil modification or stabilization. Indiana Department of Transportation, 2015.
[3] ACI COMMITTEE 116, Cement and Concrete Terminology (ACI 116R-00), American Concrete Institute, 2000.
[4] A. Rezaei, Effect of silica fume and curing time on volume change characteristics of rice husk ash stabilized expansive soil, Eastern Mediterranean University (EMU)-Doğu Akdeniz Üniversitesi (DAÜ), 2014.
[5] Ö. Çakır, Ö.Ö.J.H.J. Sofyanlı, Influence of silica fume on mechanical and physical properties of recycled aggregate concrete, 11(2) (2015) 157-166.
[6] S.M.M. Karein, A. Ramezanianpour, T. Ebadi, S. Isapour, M.J.C. Karakouzian, B. Materials, A new approach for application of silica fume in concrete: Wet granulation, 157 (2017) 573-581.
[7] E. Kalkan, S.J.E.G. Akbulut, The positive effects of silica fume on the permeability, swelling pressure and compressive strength of natural clay liners, 73(1-2) (2004) 145-156.
[8] A. Vakili, M. Selamat, H. Moayedi, H. Amani, Stabilization of dispersive soils by pozzolan, in: Forensic Engineering 2012: Gateway to a Safer Tomorrow, 2013, pp. 726-735.
[9] M.Y. Fattah, À.A. Al-Saidi, M.M.J.I.J.o.G. Jaber, Characteristics of clays stabilized with lime-silica fume mix, 134(1) (2015) 104-113.
[10] A. Goodarzi, S. Goodarzi, H.J.I.J.o.S. Akbari, T.T.o.C. Engineering, Assessing geo-mechanical and micro-structural performance of modified expansive clayey soil by silica fume as industrial waste, 39 (2015) 333-350.
[11] R.J.B.I.P.d.l.S.C. Olar, Arhitectura, Nanomaterials and nanotechnologies for civil engineering, 57(4) (2011) 109.
[12] N. Khalid, M.F. Arshad, M. Mukri, K. Mohamad, F.J.E.J.o.G.E. Kamarudin, Influence of nano-soil particles in soft soil stabilization, 20(2015) (2015) 731-738.
[13] The Royal Society, Nanoscience and Nanotechnologies: Opportunities and Uncertainties, The Royal Society & the Royal Academy of Engineering, 2004.
[14] N. Ghasabkolaei, A.J. Choobbasti, N. Roshan, S.E.J.A.o.C. Ghasemi, M. Engineering, Geotechnical properties of the soils modified with nanomaterials: a comprehensive review, 17(3) (2017) 639-650.
[15] S.M. Haeri, A. Mohammad Hosseini, M.M. Shahrabi, S. Soleymani, Comparison of strength characteristics of Gorgan loessial soil improved by nanosilica, lime and Portland cement, in: 15th Pan American Conference on Soil Mechanics and Geotechnical Engineering, 2015.
[16] B.J.E.G. Iranpour, The influence of nanomaterials on collapsible soil treatment, 205 (2016) 40-53.
[17] S.H. Bahmani, B.B. Huat, A. Asadi, N.J.C. Farzadnia, B. Materials, Stabilization of residual soil using SiO2 nanoparticles and cement, 64 (2014) 350-359.
[18] S.G.S. Alireza, M.S. Mohammad, B.M. Hasan, Application of Nanomaterial to Stabilize a Weak Soil, (2013).
[19] A.J. Alrubaye, M. Hasan, M.Y.J.I.J.o.G.E. Fattah, Stabilization of soft kaolin clay with silica fume and lime, 11(1) (2017) 90-96.
[20] ASTM D422-63, Standard Test Method for Particle-Size Analysis of Soils, ASTM International, West Conshohocken, PA, 2007.
[21] ASTM D4318-05, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils, ASTM International, West Conshohocken, PA, 2005.
[22] ASTM D2487-11, Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System), ASTM International, West Conshohocken, PA, 2011.
[23] ASTM D854-02, Standard Test Method for Specific Gravity of Soil Solids by Water Pycnometer. ASTM International, West Conshohocken, PA, 2002.
[24] ASTM D698-00a, Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort. ASTM International, West Conshohocken, PA, 2000.
[25] ASTM D2166 / D2166M-13, Standard Test Method for Unconfined Compressive Strength of Cohesive Soil. ASTM International, West Conshohocken, PA, 2013.
[26] ASTM D1883-99, Standard Test Method for CBR (California Bearing Ratio) of Laboratory-Compacted Soils. ASTM International, West Conshohocken, PA, 1999.
[27] P. Sivapullaiah, A. Sridharan, K.J.P.o.t.I.o.C.E.-G.I. Bhaskar Raju, Role of amount and type of clay in the lime stabilization of soils, 4(1) (2000) 37-45.
[28] S.H. Bahmani, N. Farzadnia, A. Asadi, B.B.J.C. Huat, B. Materials, The effect of size and replacement content of nanosilica on strength development of cement treated residual soil, 118 (2016) 294-306.
[29] Y. Qing, Z. Zenan, K. Deyu, C.J.C. Rongshen, b. materials, Influence of nano-SiO2 addition on properties of hardened cement paste as compared with silica fume, 21(3) (2007) 539-545.
[30] A. Mostafa, M.S. Ouf, M.J.I.J.o.S. Elgendy, E. Research, Stabilization of Subgrade Pavement Layer Using Silica Fume and Nano Silica, 7(3) (2016).
[31] Z. Zhang, B. Zhang, P.J.C. Yan, B. Materials, Comparative study of effect of raw and densified silica fume in the paste, mortar and concrete, 105 (2016) 82-93