This paper presents the results of a laboratory investigation exploring the effects of varying degrees of pulverization, from laboratory-quality gradations to field gradations, on the strength and durability of highly plastic clay soils stabilised with lime and portland cement. Background information is presented on the mechanisms of stabilisation and on previously reported studies of other materials.A 6-cu yd sample was used to provide 198 large specimens, which were tested in unconfined compression and wet-dry tests. Considerable differences were found in the strength of a highly active clay soil, depending on the gradations used to make specimens. Significant differences were found in the durabilities of specimens, depending on the stabilizer and the gradations used. Lime appears to be a more effective stabilizer for durability and portland cement more effective for strength, provided the gradation is fine enough. Recommendations, subject to further research, include longer curing times and the use of field gradations for all mix designs.
Abstract