Effect of compaction energy on CBR and compaction behaviour

The study reported herein examines the effect of compaction energy on the compaction characteristics and California bearing ratio (CBR) value of soils. The study involved two soils of widely varying plasticity, and led to a logarithmic relationship between the maximum dry density and compaction energy, and the relationship between the optimum moisture content and compaction energy is represented by a second-degree polynomial equation. Correlation between the CBR value and compaction energy is represented by a two-parameter linear model. The numerical values of the coefficients in the developed correlations are almost independent of the method of energy reduction and marginally dependent on the soil type. The study also re-establishes that the optimum moisture content and maximum dry density of fine-grained soils are uniquely related, with the correlation being independent of the energy ratio.