Evaluation of Witczak E* predictive models for the implementation of AASHTOWare-Pavement ME Design in the Kingdom of Saudi Arabia

• NCHRP1-37A yielded better E* values compared to NCHRP 1-40D model at all binder characterization input levels.
• NCHRP1-37A E* model with Level 3 binder characterization produced the most accurate and the least biased estimates.
• Because of the hot desert climate in KSA, care should be taken when using such models for E* predictions.

AASHTOWare-Pavement ME Design is the production version of the Mechanistic-Empirical Pavement Design Guide (MEPDG) which includes two different models for hot mix asphalt (HMA) dynamic modulus (E*) prediction. The first model is the NCHRP 1-37A while the second one is the NCHRP 1-40D model. This paper focuses on the implementation of the ME Design in the Kingdom of Saudi Arabia by developing a database containing mechanical properties of a wide variety of HMA mixtures. Then checking the predictive power of both models using the developed database. Laboratory E* tests were conducted on 25 different HMA mixtures. Dynamic Shear Rheometer and Brookfield tests were also conducted on the binders. Results showed that the performance of the investigated models varied by temperature and the binder characterization method. The results also showed that the NCHRP 1-37A E* model along with Level 3 binder inputs yielded the most accurate and least biased E* estimates.