COMPACTION SPECIFICATION FOR THE CONTROL OF PAVEMENT SUBGRADE RUTTING

Soil compaction is a primary measure for controlling permanent deformations of pavement subgrade materials. Major parameters in any compaction specfication include the compaction moisture content, compacted density, and depth of compaction. An analytical procedure for predicting subgrade rut depth (permanent deformation) based on the resilient and permanent deformation characteristics of the subgrade is presented. Rut depths associated with a range of values for the major compaction parameters are evaluated for highway pavements using this new procedure. The analytical results suggest a new criterion for compaction moisture content that minimizes subgrade rutting. Contour plots illustrating the trade-offs among compaction level, compaction depth, and natural subgrade conditions are also presented.