Experimental And Analytical Study On A Novel Perfobond Strip Connector

To reduce manufacture difficulty in making rebars get through circular perfobond rib shear connector and improve the composite behavior efficiency and applicability, two new type of steel-concrete connection was proposed:(a) a new type of perfobond rib shear connetor which is welded with horizontal headed stud(S-PBL for short);(b) a new type of perfobond rib shear connector which has two pieces of unparalleled ribs(NP-PBL for short).To evaluated the behavior of those two new types of perfobond rib shear connector, the following work has been completed:(1) Five groups of push-out tests with ten specimens were carried out to investigate the influence of the number of connector holes, the number of horizontal headed stud, the presence of reinforcing steel bars at the connector holes and the relative position of two ribs on the strength, and ductility. Tests showed that:(a) S-PBL is superior in shear resistance and ductility than conventional perfobond rib shear connector.(b) The failure modes and force-bearing mechanism of the headed stud and perfobond rib are different. Furthermore, S-PBL has advantage of both headed stud shear connector and perfobond rib shear connector.(c) By comparison with traditional Twin-PBL,NP-PBL is superior in shear resistance.(2) A three dimensional non-linear finite element model using a general purpose finite element software program ABAQUS is developed herein to study the behaviour of steel anchors for both S-PBL and NP-PBL. The pertinent results obtained from the finite element analysis were verified against experimental results. Moreover, it is observed from the comparison that the proposed non-linear model is capable of predicting the ultimate strength of the steel anchors to an acceptable accuracy.(3) The three-dimensional finite element model is used in the parametric study to investigate the influence of the distance of rib and the angle between the central axes of steel flange and axes of the rib on the strength and ductility to NP-PBL. The results indicated that the strength and the load-slip behaviour of composite steel-concrete specimens is greatly influenced by the changes of the relative location of the two ribs. The results suggested that the strength of the shear connector increased as the distance of the ribs increased. It was also found that the increase in the angle between the central axes and the rib improved the strength of the shear connector.(4) The limit state formulas for perfobond rib shear connector in shear specifically in composite construction have been assessed versus a quantity of monotonic push-out experiments from the literature. In addition, the connector resistances are compared to existing analytical formulations. Finally, an analytical formulation developed in the scope of this study for this specific shear connector type is presented and its performance compared to the test results from the current series showing a good correlation.This paper may provide a reference for the design and construction of steel-concrete composite structure.