1. Ph.D. Candidate, Dept. of Construction Engineering and Management, School of Civil Engineering, National Technical Univ. of Athens, 9 Iroon Polytechniou St., 157 73 Athens, Greece (corresponding author).
2. Associate Professor, Dept. of Construction Engineering and Management, School of Civil Engineering, National Technical Univ. of Athens, 9 Iroon Polytechniou St., 157 73 Athens, Greece.