Recent research on composite beams with demountable shear connectors

This paper presents the experimental and numerical investigations of an innovative composite floor system with deconstructability. In this system, a composite slab formed with metal profiled decking is connected to a steel beam using demountable shear connectors. A series of push tests was conducted to investigate the behaviour of this form of shear connector. In addition to the push tests, a full-scale composite beam was tested to failure in the laboratory under a number of cycles of monotonic loading. For direct comparison, a similar composite beam test was conducted using the same section size and concrete strength, but using conventional welded headed stud connectors. Test results showed that the behaviour of the composite beam with demountable shear connectors is comparable with that of the specimen with welded shear connectors. After the test was terminated, the demountable shear connectors were unfastened and the composite floor could be easily lifted off from the steel beam. Test results showed that these demountable shear connectors possess high ductility in comparison to the equivalent welded shear connectors. Simple design rules currently use in Eurocode 4 for welded shear connections and Eurocode 3 for bolts are proposed to predict the shear resistance of this form of demountable shear connector.