Resilient modulus–moisture content relationships for pavement engineering applications

Abstract

In recent years, there has been an increased interest in determining the influence of moisture changes on the resilient modulus (MR) of subgrade soils beneath pavement structures. Efforts have also been made to develop mathematical models that predict the change in MR values with moisture. These models are expected to account for seasonal variations in subgrade moisture content. This study evaluates the variation of resilient modulus with post-compaction moisture content of soils in the State of Oklahoma and the State of Pennsylvania. A series of specimens was compacted at optimum moisture content and then tested for resilient modulus; other series of specimens were prepared at optimum moisture content and then either wetted or dried prior to MR testing. Employed wetting and drying procedures are time-efficient in developing the MR–moisture relationships. Results showed that MR–moisture content relationships varied with soil types and MR values varied inversely with changes of moisture content. In addition, an MR–moisture model predicting the variation of resilient modulus with moisture contents is proposed. This model can be used to predict changes in the bearing capacity of pavements due to seasonal variations of moisture content.