Experimental study and numerical simulation on the transverse force transmission mechanism of discretely connected precast RC floor

Abstract

An innovative discretely connected precast RC floor (DCPCF) is presented, in which precast flat slabs (solid slab, sandwich slab or hollow slab) and spandrel beams (walls) are the basic components that connected by distributed mechanical connectors. The experimental program consisting six full-scaled DCPCF specimens and two cast-in-situ slab (CIS) specimens were conducted to evaluate the influence of slab joint structure on force transmission mechanism of DCPCF in orthogonal slab laying direction (OSLD), which in terms of the failure mode, deflection, strain development, etc. The results revealed that the slab joint connectors of DCPCF had good force transmission performance in OSLD, which can effectively transmit the flexural moment and connect the adjacent precast slab. Compared with CIS specimens, DCPCF specimens had no obvious plastic stage and entered elastoplastic stage earlier. The deflection of DCPCF in OSLD was mainly caused by the opening deformation of the slab joint and the rotational deformation of the precast slabs. For DCPCF specimens, the more connectors in each slab joints or the fewer slab joints, the greater the flexure stiffness in OSLD. Based on the test results, finite element models (FEMs) were developed to simulate force transmission mechanism of DCPCF in OSLD, and the accuracy was confirmed by the test results. Finally, it was verified that increasing the number of anchor bars and increasing the diameter of diagonal anchor bars can effectively enhance the anchoring measures of slab joint connectors to achieve replaceability of perforated steel plates.