EXPERIMENTAL INVESTIGATION ON THE SHEAR RESISTANCE OF I-SHAPED PERFORATED CONNECTORS IN COMPOSITE BEAMS

Introduction: Steel-concrete composite girders have been widely used in bridges, with the stability of the interface being crucial. Shear connectors and reinforced concrete slabs play a key role as interfaces. Understanding the interaction between the composite beam and slab is essential for predicting the overall system response. It is necessary to optimize the connection between steel beams and reinforced concrete slabs in steel-concrete composite girders and facilitate their assembly and installation on-site, emphasizing their pivotal role in upholding the structural integrity of composite systems. The purpose of the study was to conduct an experimental investigation and a numerical simulation using the finite element method. During the study, the following methods were used: examining the behavior of IPE and IPN perforated shear connectors using push-out tests. The main objective was to analyze how the I-shaped perforated connector, concrete slab, steel beam, and rebar affect the measured slip between the steel beam and concrete slab. To achieve that, specimens with IPE80 or IPN80 shear connectors having circular or long cut holes containing 8 mm or 6 mm diameter steel bars were used to enhance the connector’s resistance against uplift forces. The test setup follows Eurocode 4 guidelines, focusing on hole shape and anti-lift rebar diameter parameters. The predominant failure modes were mainly dictated by the crushing of the concrete slab. As a result, it was found that the hole geometry of IPE and IPN perforated shear connectors significantly impacts shear load capacity and ductility. The long cut hole shape in IPE and IPN perforated shear connectors exhibits superior ultimate load capacity but less interfacial slip compared to the circular hole. The IPE and IPN perforated shear connectors demonstrated satisfactory ductility for all tested hole shapes, and the 3D finite element models are consistent with the test results.