Pull-out behavior of non-prestressed steel strands in novel beam-to-column connection

The Precast Prestressed Assembled Structural (PPAS) system frame structure has been gradually applied in building and storage structures. In this building system, the 15.2-mm high-strength steel strands are used as the bottom longitudinal reinforcement of the precast beam, and a certain length of non-prestressed steel strands reserved at the beam ends are anchored into the concrete column to form a novel beam-to-column connection. For a reliable design of the connection joint, the mechanical behavior of this connection should be taken into account. This paper summarized the results obtained in the pull-out tests of the steel strands with different research variables, including anchorage form, anchorage position, and embedment length, and it was found that the use of the steel strand with 90-degree hooked anchorage form in the concrete column significantly affected the pull-out behavior of steel strand, such as failure mode, pull-out load versus slip curve, and ultimate load, etc. In particular, compared to the specimens of steel strands with straight-line form, the specimens having steel strands with 90-degree hooked form shows a 62% increase in ultimate load in average.