1. Ph.D. Student, Dept. of Civil, Environmental, and Natural Resources Engineering, Luleå Univ. of Technology, Luleå 971 87, Sweden (corresponding author).
2. Senior Lecturer, Dept. of Civil, Environmental, and Natural Resources Engineering, Luleå Univ. of Technology, Luleå 971 87, Sweden.
3. Professor, Dept. of Civil, Environmental, and Natural Resources Engineering, Luleå Univ. of Technology, Luleå 971 87, Sweden; Concrete Specialist, Skanska AB, Göteborg 412 65, Sweden.
4. Professor, Dept. of Civil, Environmental and Natural Resources Engineering, Luleå Univ. of Technology, Luleå 971 87, Sweden.