Effect of Coarse Content on Compaction Test

The compaction is a mechanism to densify the loose soils. The maximum soil densification can be achieved by optimization of the desirable optimum moisture content (OMC) and maximum dry density (MDD). The maximum dry density and the optimum moisture content were affected by several parameters. The coarse content (CC) is one of these parameters. This paper studied the effect of the coarse content on the compaction parameters (MDD, OMC). Several sand-kaolin mixtures had coarse content ranged from 30 % to 80 % and moisture content ranged from 12% to 20% were used to inspect the relationship between CC, specific gravity (Gs), MDD, OMC, and bulk density. The results presented five empirical correlations with coefficient of determination (R2 ≥ 0.98) between CC, Gs, MDD, OMC and bulk density. The comparison between the current study and previous researchers indicated that both soil type and moisture content have significant effect on the efficiency of the empirical correlation equations between the maximum dry density, specific gravity, and coarse content. The results indicated a linear relationship between coarse content toward maximum dry density and specific gravity where both MDD and Gs increased with an increase CC. In contrary, the results showed non-linear relationship between optimum moisture content and coarse content where OMC decrease with an increase CC.