Experimental investigation of the overall pull-out behavior of group anchored straight-type steel strands

Abstract

The Precast Prestressed Assembled Structural (PPAS) system frame is a novel prefabricated concrete structure, which has been widely applied in building and storage structures due to the advantages of the large structural bearing capacity, high construction efficiency, low cost, and the overall structural performance is not lower than the cast-in-place structure system. Good beam-to-column connection performance is a prerequisite for the PPAS system to bear the external load. However, the non-prestressed steel strand group anchor technology used in the beam-to-column connection of the PPAS system is still lacking corresponding research. For this reason, the overall pull-out tests on 2 single anchor specimens and 10 group anchor specimens of straight-type steel strands with a nominal diameter of 15.2-mm were performed in this research. The results indicated that the pull-out failure of steel strands is the main failure mode for single anchor and group anchor specimens. Meanwhile, the anchorage type of test specimens had no significant effect on the pull-out load-slip response, except for the slight difference in the linear elastic ascending stage. Furthermore, as the arrangement form (layout quantity) of the steel strands increased, the ultimate anchorage capacity of the specimens presented a nonlinear growth trend, whereas the anchoring efficiency of group anchor specimens exhibited a three-stage variation law of sharp attenuation, slow attenuation, and fast attenuation. the ultimate anchorage capacity of group anchor specimens increased linearly with the embedment length of the steel strand.