Cyclic tensile-compressive tests on thin concrete boundary elements with a single layer of reinforcement prone to out-of-plane instability

The growing need for residential housing in Latin American countries has led to the construction of reinforced concrete buildings with wall thicknesses as low as 8-10 cm. Such walls have typically only a single layer of vertical rebars and are therefore particularly susceptible to out-of-plane failure. To investigate the response of the corresponding wall boundary elements, twelve reinforced concrete columns with a single layer of vertical rebars were tested under tension-compression cycles. The objective of this test series was to gain insights into parameters triggering wall instability and out-of-plane failure. The experimental tests investigate the effect of thickness, reinforcement ratio, and eccentricity of the longitudinal rebars with respect to the element axis. This paper summarises the results of the test campaign. The specimen response is analysed at the global and local level, and the influence of the crack pattern on the out-of-plane response of the column and the conditions leading to out-of-plane failure are described. Furthermore, the differences between members with a single layer of vertical rebars to members with two layers are discussed. The influence on the response of the parameters analysed in the experimental campaign is addressed, showing that section with small thickness and large reinforcement content are more prone to out-of-plane failures. Finally, the predictions of existing models are compared to the new experimental data. The entire data set is publically available.