The Influence of Clod Size and Moisture Condition on the Shearing Behavior of Compacted Lean Clay

The purpose of this research was to study the influence of clod size and initial moisture content (which affects the moisture condition of clods) on the shearing behavior of a moderately plastic clayey soil (lean clay). Two initial moisture conditions were achieved by using two different moisture curing times of 0 and 14 days. For the 0-day curing time, samples were directly compacted after the addition of water. As for the 14-day samples, the soil was mixed with water, cured for two weeks, and then compaction occurred at the end of the curing time. The clods were divided into categories each having a range of different nominal diameters, and then two groups of samples were prepared; samples with large clods (LC = clod size less than 38 mm) and samples with small clods (SC = clod size less than 4.75 mm). All samples, however, were compacted at constant volume using the same specifications (95 percent of maximum dry density and 2 percent dry of optimum moisture content). Constant water content, unsaturated triaxial compression tests were performed at three different confining pressures in order to determine the influence of clod size and moisture condition on the shearing behavior of compacted soil. The results of this study suggest that the shearing behavior of compacted soils is significantly influenced by the size of the clods as well as their moisture conditions. At 0-day curing time, samples prepared using large clods were found to be stiffer and stronger than those prepared using small clods. However, at 14-day curing time, the strength of both LC and SC samples were similar.