Steel-concrete composite beam-column connections utilizing prefabricated permanent steel form

Abstract

To facilitate fast-built and economical constructions, a unique composite moment frame system with prefabricated permanent steel form is presented. A conventional steel wide flange beam is used at the mid-span of horizontal member which has typically small design forces. The so-called composite mechanism between the concrete and steel is utilized selectively on the beam-column connection regions of the moment frame structure, which requires higher strength and ductility demands compared to those in the mid-span. For this purpose, the permanent steel plate forms are prefabricated to the beam-column connection regions before composite with cast-in-place concrete. Since the steel beam is first connected to the steel columns, no additional false work requires during constructions, and high seismic performances can be secured at the beam-column joints, where the structural integrity should be firmly ensured. In this study, full-scale cyclic loading tests were carried out considering the various details at the connection regions as the key experimental variables to evaluate the seismic performances of the proposed composite system. Test results showed that the proposed method fully satisfies the required performances to be accepted as the composite special moment frame specified in the current design code.