Volume 2, No. 2, 2008
Received: 2008/08/27, Accepted:
Authors:
O. Al-Hattamleh; M. R. Razavi; B. Muhunthan;
Abstract:
The maximum dry density and optimum moisture content obtained from the laboratory compaction curve have
been used customarily to characterize the field behavior of compacted soils. It is well known, however, that the
microstructure of compacted soils is dependent on the method of compaction. The structure has an important
influence on the engineering behavior of compacted soils. Therefore, in order to provide a better description of
compacted soils, methods that can quantify the changes in microstructure are needed. In this study, compacted
specimens at various densities and water content were scanned using X-ray Computed Tomography (CT). It has
been found that there is direct correspondence between the CT numbers, soil dry density and moisture content.
The scanning observations showed also the development of shear planes parallel to the surface of the compacted
soil, and changes in structure of the soil towards a more uniform arrangement around the point of optimum
moisture content. Compaction of the soil beyond the optimum moisture content appears to disperse soil particles
with an overall uniform structure.
Keywords:
Computed tomography, Compaction, Dry density, Moisture content, CT numbers, X-ray.