EXPERIMENTAL AND THEORETICAL STUDY ON THE BEHAVIOR OF THE STEEL-CONCRETE COMPOSITE BEAM WITH NOTCHED WEB OF INVERTED T-SHAPED STEEL SECTION AT CONSTRUCTION STAGE

摘要

The behavior of the steel-concrete composite beam with notched web of inverted T-shaped steel section at construction stage is investigated in this paper. The composite beam is composed of concrete slab and inverted T-shaped steel beam, and the notched web of the steel beam is embedded in concrete slab as trapezoid shear connectors. When the strength of the concrete has not been fully developed at construction stage and the steel beam with inverted T-shaped section is likely to buckle in lateral direction. For preventing this, using cushion blocks at the bottom flange of the steel beam to support the vertical load during the construction of the composite beam is proposed. The experimental studies on four specimens are conducted to investigate the behavior of the steel beam with notched web of inverted T-shaped steel section at the construction stage. The theoretical analysis is carried out for critical buckling capacity of the composite beam with loads on single or both sides of the web and formulas for predicting the critical capacity of the beam are proposed respectively. The effectiveness of the formulas is verified by comparing the predicted results of the specimens' tests with the results measured from tests and obtained with FEM.