VOLUME CHANGE AND SHEAR BEHAVIOR OF COMPACTED CLAYSAND/GRAVEL MIXTURES

Year 2012, Volume: 4 Issue: 1, 52 - 66, 01.03.2012

H. Soltani-jigheh K. Jafari

Abstract

Compacted clayey soils are used as hydraulic barriers in earth structures, such as core of earth fill dams, landfill liners, and etc. These soils have some defects from technical points of view. Mixing of these soils with granular materials (e.g. sand and gravel) is one of the soil improvement methods. A number of shrinkage, direct shear and triaxial tests are carried out on the mixtures of clay and sand/gravel. The results reveal that the values of shrinkage and swellingin the mixed clayey soils (in comparison with pure clay) decrease due to adding aggregates. Moreover, the inclusion of sand/gravel to the clays beyond a threshold value improves their shear strength and the values of shear strength and shrinkage depend on the size of grains added to the clay. Results of triaxial tests also indicate that the behavior of mixed specimens are changed from contractive to dilative with increasing of aggregates in the mixtures

Keywords

Mixed clayey soils, shrinkage, shear strength, laboratory tests

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