Shrinkage strain characterization of expansive soils using digital imaging technology

Poor characterizations of shrinkage potentials of soils eventually lead to heave distress problems in expansive soils. Manual measurements in laboratory environments often result in the poor shrinkage strain characterizations. In the present research, digital imaging technology was used to measure shrinkage strain potentials of expansive soils. An experimental program was designed to measure the linear shrinkage strain, areal shrinkage strain (digital measurements), and volumetric shrinkage strains (manual and digital measurements) of four control (two natural and two artificial clays) and four cement treated soils at different compaction moisture contents.; Shrinkage strain potentials measured using digital imaging technology were higher than conventional manual measurements. Measurements were repeatable and also reliable since they accounted for irregular cracking patterns on soil samples. Correlations were developed between digital and manual measurements of both linear and volumetric shrinkage tests for future conversions and characterizations. Also, natural clays exhibited higher shrinkage strains than artificial clayey soils due to the presence of Montmorillonite clay minerals. Digital measurements of strains showed significant variations with manual measurements for all soils including cement treated soils at all ranges of shrinkage strains.