Resilient modulus for unbound granular materials and subgrade soils in Egypt

¹ Public Works Eng. Dept., Faculty of Engineering, Mansoura University, Mansoura, Egypt
² Structural Eng. Dept., Faculty of Engineering, Mansoura University, Mansoura, Egypt
³ Department of Civil and Environmental Engineering, University of Sharjah, Sharjah, UAE

^* Corresponding author: marab@sharjah.ac.ae

Abstract

Mechanistic Empirical (ME) pavement design methods started to gain attention especially the last couple of years in Egypt and the Middle East. One of the challenges facing the spread of these methods in Egypt is lack of advanced properties of local soil and asphalt, which are needed as input data in ME design. Resilient modulus (M_r) for example is an important engineering property that expresses the elastic behavior of soil/unbound granular materials (UGMs) under cyclic traffic loading for ME design. In order to overcome the scarcity of the resilient modulus data for soil/UGMs in Egypt, a comprehensive laboratory testing program was conducted to measure resilient modulus of typical UGMs and subgrade soils typically used in pavement construction in Egypt. The factors that affect the resilient modulus of soil/UGMs were reviewed, studied and discussed. Finally, the prediction accuracy of the most well-known M_r Prediction models for the locally investigated materials was investigated.