Influence of Water Content on the Structure and Physical Properties of Compacted Soils

Studies on the relations between physical and engineering properties and soil structure of clayey soils (VI)

Abstract

The structure of volcanic ash soils compacted at different molding water contents was evaluated by their shrinkage behaviors, and the significance of the molding water content on the structure and physical properties of compacted soils was considered.
1) Two types of volcanic ash soil used did not have optimum water content in the compaction curves.
2) Saturated hydraulic conductivity ( “K₁₅”) and water content under pF 3 ( “θ<pF 3”) of the compacted soils showed an abrupt increase at just a little lower molding water content than a certain value.
3) “Structural pore” as the structural index of the compacted soils was defined on the basis of the shrinkage behavior.
4) Structural pore volume was closely related with K₁₅ and θ<pF 3 of compacted soil.
5) The molding water content showing an abrupt increase in the structural pore, K₁₅ and θ<pF3 agreed with the transitional water content from the structural shrinkage to the normal-like shrinkage in the shrinkage curves of undisturbed soil.