Experimental and numerical analysis on timber-concrete connections with glued reinforcing bars

Abstract

Shear connectors have a great influence on the mechanical behavior of timber-concrete composite structures, interfering with the stiffness and strength of the structural elements. This paper presents experimental and numerical studies about the mechanical behavior of timber-concrete composite structures by evaluating two types of connectors: one formed by an inclined rebar and another formed by the association of an inclined rebar with a triangular notch. The rebars used were ribbed-type with yield strength equal to 500 MPa, and their fixation on timber was made by gluing with epoxy resin. The experimental determination of the strength, the slip modulus and the failure modes were made by means of push-out tests. Subsequently, a numerical evaluation using ABAQUS was carried out in order to develop a three-dimensional numerical model that represented these types of connections, considering the nonlinearities of the materials, the orthotropy of timber and the interaction between the components. It was observed that the notch connection showed greater strength and stiffness when compared to the connection without notch. The comparison between the numerical and experimental results showed that the numerical model was able to predict, with good approximation, the failure load and the slip modulus of the connection without notch, while the stiffness of the numerical model proved to be higher than that observed in the experimental analysis for the notch connection.