Proceedings of Eurosteel 2008, 5th European Conference on Steel and Composite Structures, research-practice-new materials, Graz, September 2008, 1557-1562 STARTPAGE=1557;ENDPAGE=1562;TITLE=Proceedings of Eurosteel 2008, 5th European Conference on Steel and Composite Structures, research-practice-new materials, Graz, September 2008