The strength of remoulded soils as affected by exchangeable cations and dispersible clay

• Published in: Australian journal of soil research Vol. 32
• Main Authors: Barzegar A.R, Murray R.S, Churchman G.J, Rengasamy P
• Format: Journal Article
• Language: English
• Published: 1994
• Subjects: arcilla; argile; cation; cationes; cations; clay; echange d' ion; esfuerzo del suelo; intercambio ionico; ion exchange; resistance mecanique; resistance mecanique du sol; resistencia mecanica; sodio; sodium; soil strength; strength
• ISSN: 0004-9573; 1446-568X
• DOI: 10.1071/SR9940185

The tensile strength of remoulded samples of 5 Australian soils with differing clay type, texture and shrink-swell potential changed with the nature of the exchangeable cation, clay content and amounts of spontaneously and mechanically dispersible clay. Multiple regression analyses indicated that spontaneously dispersible clay alone was a major predictor of the tensile strength of remoulded sodic soils. Analysis of variance of data for all the soils with varying exchangeable Na percentage (ESP) values showed that spontaneously dispersible clay was strongly correlated with clay content. Analyses of data for individual soil type showed that spontaneously dispersible clay was highly correlated with ESP. For each soil studied, increase in the ESP resulted in increase of dispersible clay and hence in tensile strength. Although tensile strength increased with ESP, the rate of change of strength with ESP was different for each soil. Soil with the highest clay content gave rise to the greatest rate of change. The effect of exchangeable Ma on tensile strength was similar to Ca. However, in 2 of the soils, exchangeable Ma, in the presence of Na, increased the strength slightly more than Ca, confirming the ionic radius effect of these elements.