Effect of Stone Powder and Lime on Strength, Compaction and CBR Properties of Fine Soils

This research is an attempt to investigate the effect of stone powder and lime on the strength, compaction and CBR properties of fine grained soil. The basic properties: direct shear, compaction and CBR were determined first. The stone powder and lime were added at specific percentages (10%, 20% and 30%) by weight of soil and mixed with the optimum moisture content obtained from the compaction test. The direct shear, compaction and CBR tests were conducted directly without curing or soaking of the specimens. The results revealed that the addition of 30% stone powder has increased the angle of internal friction (φ) by about 50% and reduced cohesion by about 64%. The addition of 30% of lime has decreased the friction angle and cohesion by 57% and 28%, respectively. The maximum dry density and optimum moisture content decreased slightly by addition of 30% stone powder, however, the addition of 30% lime decreased the maximum dry density and optimum moisture content by 19% and 13.5%, respectively. The CBR values have increased from 5.2 to 16 and 18 by the addition of 30% stone powder and lime, respectively. The thicknesses of flexible pavement were determined based on the CBR values and assumed daily traffic volume and found to be reduced from 38 cm for soil without additives to 20 cm and 17cm by the addition of 30% of stone powder and lime, respectively.