Simple prediction model for plastic deformation of graded crushed stone base for flexible pavement

Plastic deformation behaviour of graded crushed stone (GCS) base affects the service life of flexible pavement. This paper presents a simple prediction model to characterize the plastic deformation behaviour of GCS base. A relative deformation model was proposed based on the deformation model developed by Pérez. The plastic deformation test was conducted using a rutting tester under different moisture contents, test times, aggregate gradations and load stresses, respectively. The model coefficients were calibrated, and the model was validated by comparing the measured value and predicted value of relative deformation under different test conditions. The plastic deformation model for GCS base, based on the relationship between relative deformation and plastic deformation ratio, was ultimately determined by taking a standard stress of 0.7 MPa and the plastic deformation of GCS in the 60th min corresponding to this stress as the reference standard. The correlation coefficient (R2 > 98%) indicates that the developed model has a desirable prediction accuracy. The developed model can be used to predict the plastic deformation of GCS base, evaluate its plastic deformation performance and provide support for highway maintenance management.