Impact of subgrade stabilisation on perpetual pavement structural response

Perpetual Pavement is a long-life pavement designed to serve more than 50 years without major rehabilitation (APA, 2002). Chemical subgrade stabilization improves soil properties through additives such as lime or cement, creating a strong platform that promotes stress confinement in upper layers and reduces stress transmission to deeper layers. ODOT now mandates subgrade stabilization for all interstate highways, expected to enhance performance and enable conventional pavements to exhibit perpetual pavement behavior.In this study, a three-dimensional viscoelastic finite element model was developed, calibrated, and validated using field instrumentation data to evaluate the impact of lime-stabilized subgrade (45.7 cm thick with 7% lime) on pavement structural response. Results show stabilization reduces tensile strain at the bottom of the AC layer and compressive strain at the top of the subgrade, mitigating fatigue cracking and rutting. Under elevated temperatures, stabilized sections showed improved performance consistency, supporting perpetual pavement design in Ohio.