Design, manufacturing and testing of shear-cone connectors between CFRP stay-in-place formwork and concrete

Stay-in-place formwork is often used to accelerate the construction of structural elements such as flooring, concrete bridge decks and compressed shells. This study aims at designing, manufacturing and testing of two different nonlinear shear connectors made of fiber reinforced polymer composites for the formwork: (1) non-directional, cylindrical shear-cones; and (2) directional, cubical shear-cones with one side beveled. Six 1 m-long specimens were constructed using carbon fiber reinforced polymer stay-in-place formwork and a plain concrete slab (200 wide and 130 mm thick). Based on the results of three-point bending tests, similar stiffness, load-displacement response and failure mode were observed in the two contrasting designs. The resistance of the specimens using cylindrical shear-cones was approximately 26% higher than that of the ones with cubical design.