1. Assistant of Civil Engineering, Higher Institute of Technological Studies of Rades, BP 172, 2098 Radès Medina, Tunisia; Member of Laboratory of Civil Engineering, Univ. of Tunis El Manar, National Engineering School of Tunis, B.P. 37 Le Belvédère, 1002 Tunis, Tunisia (corresponding author).
2. Professor of Civil Engineering, Institut Jean Lamour, UMR 7198, CP2S, Materials for Civil Engineering, Univ. of Lorraine, IUTNB, CS 90137, F54600 Villers-lès-Nancy, France.