Geotechnical Properties of Cement-Treated Champlain Sea Clay-PPT Presentation

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The study investigated the feasibility of deep soil mixing (DSM) for improving Champlain Sea clay, a sensitive, compressible marine clay found in Ontario and Quebec. Laboratory tests assessed cement-based binders, strength development, compressibility, tensile strength, and changes in soil microstructure.<br /><br />Clay samples were mixed with binders using wet-mixing procedures and tested after different curing periods. The binders included general-use Portland cement, cement–silica fume, cement–slag, and cement–kiln dust blends. Tests included unconfined compression, consolidation, tensile strength, scanning electron microscopy, and X-ray diffraction.<br /><br />All treatments improved the clay’s strength, with strength generally increasing over time. Portland cement was highly effective, and a dosage of 100 kg/m³ was identified as the best balance of strength and cost. Cement-treated samples also showed substantially lower compressibility and higher preconsolidation pressure than untreated clay. Cement kiln dust and slag blends produced notable long-term strength gains, suggesting that they may replace some cement.<br /><br />Microscopy showed that cementitious products coated and bonded clay particles, formed larger aggregates, and filled voids. X-ray diffraction identified calcium silicate hydrate and calcium aluminium silicate hydrate in treated samples. Treatment also reduced the clay’s salinity.<br /><br />The findings support the laboratory feasibility of DSM for Champlain Sea clay. However, further research is needed to verify performance in the field, test clays from different locations and salinity levels, quantify microstructural changes more precisely, and develop a design method that accounts for variability in treated soil.

Keywords

deep soil mixing

Champlain Sea clay

cement-based binders

Portland cement

compressibility

unconfined compression

soil microstructure

calcium silicate hydrate

cement kiln dust

marine clay stabilization