1. Professor, Faculty of Civil Engineering Subotica, Univ. of Novi Sad, Kozaracka 2A, 24000 Subotica, Serbia (corresponding author).
2. Associate Professor, Faculty of Civil Engineering, Univ. of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Belgrade, Serbia.
3. Professor, Faculty of Civil Engineering Subotica, Univ. of Novi Sad, Kozaracka 2A, 24000 Subotica, Serbia.