---

Subgrade soil plays a very important role in the construction of roadways. The introduction of paving asphalt in road construction has led to the development of engineering procedures and designs for the methods of construction. The resilient modulus of the underlying material supporting the pavement is now considered as a key material property in the AASHTO mechanistic-empirical design procedure. Attempts have been made by researchers to predict the Subgrade resilient modulus from laboratory/field experimental methods based on the soil properties. A model for predicting the subgrade resilient modulus due to environmental [freeze-thaw] conditions by considering the seasonal variation of temperature and moisture content which affects the soil is developed. This model can be modified to suit other local environmental conditions.

---

Obafemi is a practicing Professional Engineer and Lecturer at the Department of Civil Engineering, Fourah Bay College, University of Sierra Leone. Andrew is a practicing Professional Engineer and Professor at the Department of Civil Engineering, University of Toledo.

---