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| MICROMECHANISM OF OVER-WET CLAYEY SOILS STABILIZED
BY CALCIUM CARBIDE RESIDUES |
| DU Yanjun，LIU Songyu，WEI Mingli，ZHU Jingjing |
| (Institute of Geotechnical Engineering，Southeast University，Nanjing，Jiangsu 210096，China) |
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Abstract To illustrate the factors controlling the strength development of calcium carbide residue(CCR) and quicklime stabilized over-wet clay soils，a series of laboratory tests including unconfined compression，soil pH measuring，mercury intrusion porosimetry(MIP) and thermo gravimetric analysis(TGA) were conducted to quantify the relationships between the unconfined compressive strength with the soil pH，the pore size distribution and the content of pozzolanic reaction product. The experimental results show that the strengths of CCR are similar to ones of quicklime stabilized soils at early stage and are 1.05 to 1.16 times higher at late stage. The fractions of clay particles，the specific surface area(SSA)，and the contents of reactive silica(Si) and alumina(Al) of CCR rebound are 1.72，5 and 1.71 times those of quicklime respectively. The pH values of the CCR stabilized soil are approximately 12.4 to 12.6 with the curing times of 28 to 120 days，which is in favor of the pozzolanic reactions between the CCR and soil particles. In addition，the pozzolanic reaction products in CCR stabilized soil are 1.06 and 1.10 times that of the quicklime stabilized soil. The sum of volumes of micro(＜0.007 μm) and small (0.007–0.900 μm) pores of the CCR stabilized soil are 1.05 and 1.23 times that of the quicklime stabilized soil when the curing times are 28 and 120 days.
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Received: 08 November 2013
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2014, Vol. 33 
