Influence of sodium silicate and promoters on unconfined compressive strength of Portland cement-stabilized clay

Abstract Eco-friendly sodium silicate and promoters, which are compatible with cement and are used to obtain super properties, have been developed into a variety of soil stabilizers. This paper investigates the possibility of using cement and sodium silicate admixed with composite promoters to improve the strength of soft clay in Shanghai, China. The influential factors involved in this study are the type of promoters, the proportion of each binding agent, the binder content, and the curing time. The unconfined compressive strength of stabilized clay at different ages is tested. Based on an orthogonal experiment, the selected clay stabilizer (CSCN) is determined. More importantly, it is found that much less CSCN is needed to achieve the equivalent improvement in strength compared with cement, which illustrates that CSCN can be a more effective and eco-friendly clay stabilizer. Mineralogical and microstructural tests are performed to reveal the possible mechanisms controlling the strength development. The effect of CSCN on cement hydration and pozzolanic reactions is discussed. Microstructural analyses confirm the formation of hydration and pozzolanic products, and show that the clay tends to form more compact microstructures after being stabilized with CSCN.

[1]  G. Gao.  THE DISTRIBUTION AND GEOTECHNICAL PROPERTIES OF LOESS SOILS, LATERITIC SOILS AND CLAYEY SOILS IN CHINA , 1996 .

[2]  Thomas L. Brandon,et al.  Rapid Chemical Stabilization of Soft Clay Soils , 2007 .

[3]  D. Hunter.  Lime-Induced Heave in Sulfate-Bearing Clay Soils , 1988 .

[4]  Arul Arulrajah,et al.  Calcium carbide residue: Alkaline activator for clay–fly ash geopolymer , 2014 .

[5]  H Böhni,et al.  The influence of alkali-free and alkaline shotcrete accelerators within cement systems: I. Characterization of the setting behavior , 2001 .

[6]  Yuzhen Yu,et al.  STUDY OF MECHANICAL PROPERTIES OF SOIL-CEMENT MIXTURE FOR A CUTOFF WALL , 1997 .

[7]  Hans-Georg Kempfert,et al.  Excavations and Foundations in Soft Soils , 2006 .

[8]  P. Chindaprasirt,et al.  Sulfate Resistance of Clay-Portland Cement and Clay High-Calcium Fly Ash Geopolymer , 2015 .

[9]  Suksun Horpibulsuk,et al.  Strength development in clay–fly ash geopolymer , 2013 .

[10]  E. Gartner.  Industrially interesting approaches to “low-CO2” cements ☆ , 2004 .

[11]  M. Jalili,et al.  Effect of Portland cement and lime additives on properties of cold in-place recycled mixtures with asphalt emulsion , 2009 .

[12]  S. Kazemian,et al.  Effect of aggressive pH media on peat treated by cement and sodium silicate grout , 2011 .

[13]  B. Huat,et al.  Influence of Cement – Sodium Silicate Grout Admixed with Calcium Chloride and Kaolinite on Sapric Peat , 2011 .

[14]  Suksun Horpibulsuk,et al.  Undrained Shear Behavior of Cement Admixed Clay at High Water Content , 2004 .

[15]  Suksun Horpibulsuk,et al.  Strength Development in Cement Stabilized Low Plasticity and Coarse Grained Soils: Laboratory and Field Study , 2006 .

[16]  Suksun Horpibulsuk,et al.  Clay–Water∕Cement Ratio Identity for Cement Admixed Soft Clays , 2005 .

[17]  Jan R. Prusinski,et al.  Effectiveness of Portland Cement and Lime in Stabilizing Clay Soils , 1999 .

[18]  Lan Kai.  Laboratory Experiment of the Anticorrosion of Cement Stabilized Soft Soil in Deep Mixing Pile , 2005 .

[19]  Yan Gao,et al.  Experimental and DEM Examinations of K0 in Sand under Different Loading Conditions , 2014 .

[20]  Theerawat Sinsiri,et al.  Properties of high calcium fly ash geopolymer pastes with Portland cement as an additive , 2013, International Journal of Minerals, Metallurgy, and Materials.

[21]  F G Bell,et al.  STABILISATION AND TREATMENT OF CLAY SOILS WITH LIME. PART 1 - BASIC PRINCIPLES , 1988 .

[22]  Tanakorn Phoo-ngernkham,et al.  Influence of curing conditions on properties of high calcium fly ash geopolymer containing Portland , 2014 .

[23]  Sudhakar M. Rao,et al.  Laboratory Studies on Stabilization of an Expansive Soil by Lime Precipitation Technique , 2012 .

[24]  C. Meyer.  The greening of the concrete industry , 2009 .

[25]  Stephanie Glendinning,et al.  LIME MODIFICATION OF CLAY SOILS FOR CONSTRUCTION EXPEDIENCY. , 1997 .

[26]  Suksun Horpibulsuk,et al.  Soil Stabilization by Calcium Carbide Residue and Fly Ash , 2012 .

[27]  C. Bing,et al.  Analysis of strength development in soft clay stabilized with cement-based stabilizer , 2014 .

[28]  Brian H. O'Connor,et al.  Chemical optimisation of the compressive strength of aluminosilicate geopolymers synthesised by sodium silicate activation of metakaolinite , 2003 .

[29]  Mingjiang Tao,et al.  Experimental feasibility study of geopolymer as the next-generation soil stabilizer , 2013 .

[30]  S. Shen,et al.  Factors influencing strength development in clay–fly ash geopolymer , 2013 .