The effect of the Initial Water Content on the Compaction Characteristics of Tropical Soils

Compaction tests have been carried out on laterite, tertiary and volcanic soils to establish the behavior of the density- moisture curve for compaction from the wet side of the optimum moisture content to the dry side as well as that from dry to the wet side. Compaction was done using fresh samples from each point. Also determined were the qualitative mineralogical composition of the clay fraction. Comparison of the maximum dry densities of the compaction from the wet side with that from the dry side did not show any significant difference. The results of the mineralogical composition revealed minerals dissimilar from those known to influence the compaction characteristics of tropical soils. This partially explained the difference in the magnitude of the dry densities variation achieved in these tests compared to the results obtained in other tropical countries. Practical implication of the results is that compaction can be carried out from either side of the optimum moisture content; since approximately the same degree of compaction is obtained in each case.