EXPERIMENTAL STUDY ON FLEXURAL BEHAVIOR OF STEEL-CONCRETE COMPOSITE BEAM COMPRISING PRECAST COMPOSITE SLABS

Four-point bending tests including twelve specimens were carried out to investigate the flexural rigidity, failure mode and ultimate capacity of the steel-concrete composite beam with a composite floor slab comprising 30 mm thick precast prestressed concrete panels and T-shaped concrete ribs (PPCRP). The test parameters included support length of PPCRP, thickness of the composite floor slab, longitudinal compressive reinforcement ratio, degree of the shear connection and the direction of T-shaped concrete rib. Strain distribution along the depth of mid-span section was obtained by strain gauges. Based on the moment-deflection curves of specimens, it was showed that flexural behavior of precast composite floor slab was similar to that of concrete floor slab cast in-situ during the elastic stage. Two failure phenomena were observed: i) Interface bond slip between the precast panel and the cast in-situ layer; ii) Diagonal shear crushing in one shear span. Compared with the floor slab cast in-situ, a slight decline in the ultimate flexural capacity was observed for the composite beam with composite floor slab. Analyses about the effects of all parameters on composite beams’ rigidity and ductility were presented.