Mechanical properties of short rebar connectors in ultra-thin lightweight composite decks

Abstract

To address the challenge of shear connector applicability in ultra-thin Lightweight Composite Decks (LWCDs), a novel type of Short Rebar Connectors (SRCs) was proposed. With the height of 16–20 mm, the connectors are well-suited for ultra-thin LWCDs with Ultra-High-Performance Concrete (UHPC) thicknesses within 35 mm. The mechanical performance of SRCs was investigated through pull-out tests, static and fatigue push-out tests. The results demonstrate that SRCs exhibit excellent tensile and shear resistance, with the maximum pull-out and shear capacities of 80.4 kN and 948 kN, respectively. The shear stiffness of SRCs is twice that of traditional stud connectors. From fatigue push-out tests, a design strength of 69.2 MPa at 2 million cycles was obtained. Finite Element Method (FEM) calculations for practical bridge engineering SRCs layout recommend arranging SRCs with a spacing of 200 mm × 200 mm.