Hysteresis and Dynamic Response Features of Concrete Exposed to Repeated Multilevel Compressive Loading

Abstract

Repeated loading can produce serious hazards to concrete constructions. In this work, hysteresis and dynamic response characteristics of concrete subjected to repeated multilevel compressive loading are investigated through laboratory tests. The influence of maximum and minimum load levels on hysteresis time and dynamic response ratio (DRR) are studied based on the laboratory test results. It is concluded that the maximum load level has a more pronounced effect on DRR and hysteresis time than the minimum load level. During the first repeated loading stage, the hysteresis time linearly increases with the maximum load level, whereas DRR shows the opposite trend. The evolution of DRR and hysteresis time of lateral strain can be subdivided into four phases, which is consistent with the trend of P-wave speed and cumulative acoustic emission (AE) counts. Hysteresis time and DRR can be used as the damage variables during the compressive repeated loading.