Jahid Zeghiche
University of Al-Baha
Saudi Arabia
Title: Further Tests on Thin Steel and Composite Fabricated Stubs
Biography
Biography: Jahid Zeghiche
Abstract
Results of tests conducted on thin cold fabricated steel-concrete stubs are presented. The studied sections were made of two cold formed steel plates with U shape welded to form a steel box or an I shaped steel section. The steel cross section dimensions were: 100x70x2. mm. The main studied parameters were: the stub height, the welding fillet nature and its location, the steel cross section shape, the in-fill concrete and its age. A total of 48 stubs were tested, 22 empty and 26 filled with concrete that gravel made of crushed slag from blast furnace as natural gravel substitution. All failure loads were predicted numerically using ABACUS and by Euro codes EC3 and EC4 for steel and composite respectively. From test results it was confirmed that the discontinuous welding fillet for empty stubs had a drastic effect on the load carrying capacity and the failure mode was rather a premature local buckling mode. I shaped steel stubs had higher compression strength a lower load decrease rate compared to rectangular steel stubs. Providing rectangular steel stubs with continuous welding on mid-depth improved the load carrying capacity for rectangular empty steel and composite stubs. Meanwhile the age of concrete at 3 years enhanced considerably the performance of rectangular composite stubs with discontinuous welding. Both numerical and test results were in good agreement whereas EC3 and EC4 predictions were not conservative.