STUDY OF A NEW MONOLITHIC STRUCTURE JOINT OF LONG-SPAN COMPOSITE PRESTRESSED CONCRETE FLOOR SLABS

There is a current research hotspot on performances of monolithic structure joints composite prestressed concrete slabs. A new monolithic structure joint of composite prestressed concrete slab was proposed, in which the rebars of the prefabricated panel were outstretched with oblique crossing, and several additional rebars were placed close to the top of the prefabricated panel. The experimental results showed that the rebars oblique-cross details of steel bars in the prefabricated panel could effectively transfer the forces between two prefabricated panels. The mechanical performances of the new joint were superior to that of the cast-in-place panel, and the specimens were destroyed on both sides of the joint. Stirrups were used to replace the truss bar, and neither the precast layer nor the composite layer of the composite concrete slab at the joint of the specimen was not disengaged when the specimen was destroyed. It indicated that stirrup bars could effectively limit the development of cracks in the precast and composite layers of concrete. The experimental results of the composite concrete slab with different thickness showed that the bearing capacity and deformation capacity of the new joint could meet the design requirements. It could provide a new idea for design of long-span composite prestressed bi-directional concrete slabs.