Research On Seismic Performance Of High-strength Concrete Short Column Reinforced With High-strength Rebar

In recent years, high-strength steel and high-strength concrete have been widely used in structural engineering. Strength of high-strength steel with no obvious yield point is higher than ordinary steel. Compared with ordinary concrete, the strength of high-strength concrete is higher but more brittleness, and this performance is unfavorable for the structure. Many scholars have researched on seismic performance of high-strength concrete structures with high-strength steel, and achieved a certain of results. However, the study of high strength concrete short columns with high-strength steel still inadequate. The seismic performance and failure mechanism of high-strength concrete columns with high-strength steel is different from ordinary concrete. Based on the theoretical analysis, a test program on the seismic performance of high-strength concrete short columns reinforced with high-strength steel under low cyclic load is presented. Specific tasks include the following aspects:(1) Reviewing recent research progress in home and abroad on the seismic performance of ordinary concrete columns and high-strength concrete columns reinforced with high-strength steel under low cyclic load.(2) Eight short model columns, in which ultra-strength rebar with the yield strength of 1420 MPa are used as the longitudinal reinforcements and stirrups, are tested under low cycle reciprocating load, to research the factors of shear span ratio, axial compression ratio, stirrup and strength of concrete which influence the seismic performance of the short column. Discusses the characteristic of the hysteresis curves, skeleton curves, stirrups and longitudinal reinforcement stress-strain curve. The results show that the configuration of high-strength concrete columns with high-strength steel are bending damage under seismic loads.(3) Based on the normal section force resistant calculate method in Chinese Code for design of concrete structures (GB 50010-2010) and relevant literatures, combining with the test results, the bearing capacity calculate method of high-strength concrete short columns reinforced with high-strength steel should be improved.(4) Recommendations for further research on seismic performance of high-strength concrete short columns with high-strength steel are given, laying the foundation for further research.