Performance evaluation of RC shear walls with mechanical couplers: Insights from tensile and Quasi-static cyclic lateral loading tests

The aim of this paper is to study the mechanical behaviour of reinforced concrete (RC) shear walls with mechanical coupler to connect longitudinal rebars. The RC walls are compared with traditional overlapping splices. The loading is done by a vertical compressive load combined with a horizontal flexural push-pull loading. When rebars are places with overlapping splices, space between rebars is missing and concrete pouring is more difficult. Local unfilled structures leads to poor quality and can question the structure behaviour, especially in large-scale constructions where local damaged can be more significant. Mechanical couplers connections reduce the risk of on-site defects by simplifying the installation of reinforcement framework and improving efficiency, particularly in large prefabricated elements. Three tests were carried out on large test specimens to assess their mechanical behavior. First, a cyclic tensile test was performed on the rebar alone to assess the performance of the BARTEC reinforcement connection. The bar manufacturing process includes a normalization step to eliminate residual stresses resulting from localized compression of the bars and threading. This approach reduces the influence of the Bauschinger effect. In a second phase, large-scale tests are done on reinforced concrete shear walls subjected on a first set of specimens to quasi-static loading and then on others specimens to cyclic horizontal loads. Some key parameters of the coupler properties are considerate such as geometry and placement along the longitudinal rebars. Rebar couplers are placed in different position. The results enhance that the use of mechanical couplers allows to improved structural performance. Mechanical parameters like the ductility, the self-centering capability and the secant stiffness are improved. The energy dissipation and the damping ratio is increased. The strength degradation is reduced. These results demonstrate that these new reinforcement connections with bar standardization achieve better results than walls with overlapping bars. Mechanical couplers are an attractive alternative for ensuring continuity in reinforced concrete reinforcement, offering increased reliability and structural performance.