Rebar Truss Stiffened Concrete Composite Beams with U-Shaped Steel Girders under Bending Moments

Experimental Study on Mechanical Performance of U‐Shaped Steel‐Encased Concrete Composite Beam‐Girder Joints

“…e strain distributions along the section depth of beams are similar to the composite beams [12,13,17,18], which were basically consistent with the plain section assumption, while those of the shaped sleeves were quite different [22]. e previously mentiond phenomenon can be mainly attributed to the insertion of the beams into the shaped sleeves, and connected by welding, a "leverage" effect could be formed on the shaped sleeves, making the shaped sleeves subjected to the pressure q, while the bottom ends of the shaped sleeves subjected to the shear force V. Under the combine action of q and V, the shaped sleeves were exposed to complex stress states and additional tensile stress formed on the web of shaped sleeves, while stress (compressive stress) concentration happened nearby the bottom ends, shown in Figure 18.…”

“…Similarly, the principal tensile stress direction of the node zone slabs changed with the position, forming arc-shaped cracks, as shown in Figures 7 and 8. e slab strain distributions in this paper are different from that of composite beams, the Specimen SCB2 [22] was under negative bending moment, and the concrete slab showed an M-shaped strain distribution. e difference is mainly due to the different force state between joints and beams.…”

“…us, several forms of shear connectors have been reported for enhancing the flexural behavior or eliminating the constitution difficulty of composite beams [14][15][16][17][18][19][20][21][22]. Park et al [14,15] used diagonal rebars and welded rebar connections to strengthen the beam-column joints.…”

“…rough experimental results, the midspan deflection of the composite beams can reach up to L 0 / 20, reflecting a good deformability. is research team [22] proposed a novel U-shaped steel-encased concrete composite beam, in which the inserted bars acted as the shear connectors (shown in Figure 3(b)), and performed static loading tests on two specimens to study the mechanical performance of composite beams under positive and negative bending moments. e results showed that the composite beam exhibited an extremely strong deformation performance under a positive bending moment, and no instability was observed on the specimen under a Advances in Civil Engineering negative bending moment.…”

“…On the basis of the previous study of this research team [22], this paper proposes a novel U-shaped steel-encased concrete composite beam-girder joint. Two full-scale specimens with slabs were tested to verify the reliability and investigate the failure modes, bearing capacity, deformation performance, and strain distributions of the novel composite beam-girder joints.…”