Behavior of Shear Connectors Formed by Bonded-in “X” Type Steel Bars in Wood-Concrete Specimens

Abstract

In Brazil, don’t have a standard code which rules the shear connector tests for mixed wood-concrete structures. Due to the excellent connector diversification, regarding shape, stiffness, limit strength and the placement in the structural member; and variables as: spaces between connectors, spaces between connectors and the member ends of wood or concrete, dimension variation and mechanical properties of the materials involved, besides the rate and reinforced grid disposition in the concrete members, several normative documents suggest that wood-concrete specimens represent the real connection behavior. In this work, were used a push-out type specimen to characterize the connectors formed by bonded-in steel bars in “X” type behaviour, with a 45º between steel bars and wood grain. In this work, were used: Corymbia citriodora wood specie, without surface treatment; Threaded surface steel bars (CA-50 steel); and reinforced concrete of medium strength. Steel bars were bonded in the wood with epoxy resin Sikadur32 fluid and anchorage in the concrete by adherence. In each steel bar, in the axial direction and in the shear plan surface, two electric extensometers were fixed in opposed points. Results present the steel bar anchorage behaviour, force distributions in the steel bars, as well as the rupture model and mechanism and the procedures to obtain the connection sliding modulus and limit strength.