Shear Behavior of Reinforced Concrete Members Under Bidirectional Reversed Lateral Loading

摘要

The influence of lateral load or deformation history on shear behavior was examined. Ten specimens were subjected to different loading histories. The dimensions and reinforcement of all test specimens were identical. Each load path or load sequence was imposed on the specimens using a specially fabricated servo-controlled loading system which applied lateral translations perpendicular to the longitudinal axis of the specimen. Rotation of the ends of the specimens was controlled to simulate a column between stiff floors. The influence on load and deformation history was examined by comparing performance in terms of shear strength deterioration, stiffness reduction, strain distribution in transverse reinforcement, and crack patterns. Based on test results, a conceptual model was developed for analyzing the shear behavior of members under multi-directional loading. The model was based on the concept of a damage index which was developed to help describe the shear failure mechanism. A sand-spring analogy was introduced as one component of the model. Details of the analytical procedure were based on measured response of the members. The model was used to estimate the shear response under various deformation histories and it is limited to members which have geometry similar to that of the members tested.