Bolted and welded connectors for the rehabilitation of composite beams

Structural Behavior of Steel-Concrete Composite Beam using Bolted Shear Connectors: A Review

“…In composite beam, the grout is used to cover the shear connectors inside the concrete slab. Based on the previous study, it is stated that the concrete grout with similar compressive strength as the concrete compressive strength did not have any substantial effect on the ultimate strength of the composite beam [10,26,37]. However, if the grout strength is lower than the strength of shear connector, then the grout in front of the connectors can experience high crushing strains during loading.…”

“…Concrete strength and grout in precast concrete slab is one of the important parameters to be considered in designing the composite beam. It is proved by most of the researches that as the compressive strengths of concrete increases, the ultimate strengths of composite beams increase, but not remarkably so [10,26,37,38]. For example, a study conducted by Liu et al stated that when the concrete strength increases from 42 to 70 MPa, the ultimate strength of the beam increases by only 5% [10].…”

Finite Element Analysis of Demountable Steel-Concrete Composite Beams Under Static Loading

“…The contact interaction was also used at the concrete-to-bolt ( Figure 5c), decking-to-concrete ( Figure 5d) and decking-to-beam ( Figure 5e) interfaces. It was found from the push-out experiment that the nut surface did not separate from the bolt surface [11]. Therefore, the bolt and nut were created as a single part as shown in Figure 5(f).…”

“…Figure 8(a) depicts the stress contour at failure of composite beams predicted from the finite element model. The failure mode of composite beam with bolted connectors was a combination of shear failure of the bolted connectors ( Figure 8b) and concrete crushing failure (Figure 8c) [11]. The shear connector failure is defined at the slip of 6 mm as shown in Figure 8(b).…”

“…The shear resistance was achieved about 84% of the headed studs at the slip of 6 mm. Further tests on full scale beams by Mirza and Uy [9] and Pathirana et al [10][11] illustrated that the steel-concrete composite beams could be loaded to very high service loads and the blind bolts could still be removed. The experimental studies conducted by Loh et al [12], Wang et al [13] and Mirza and Uy [14] illustrated the benefits of using blind bolts connections to concrete-filled steel tubular columns.…”