Experimental Study on Seismic Behavior of Steel Reinforced High-strength Concrete Column with Steel Fiber

In order to improve the brittleness of high-strength concrete and promote the seismic performance of steel reinforced high-strength concrete columns, steel fiber was used to prepare reinforced high-strength concrete column specimens, and low cycle cyclic loading tests were carried out to observe the failure process and shape of the specimens. Based on load-displacement hysteresis curve, skeleton curve and strength attenuation, the influence of steel fiber content on the seismic performance of the specimen was studied. The results show that when the volume fraction of steel fiber is in the range of 0−2.0%, the specimens with different content of steel fiber undergo bending failure, but the addition of steel fiber can delay the crack development and effectively prevent the concrete from falling off in a large area. After adding steel fiber, the hysteretic curve is fuller, and the energy dissipation capacity is significantly improved, the bearing capacity is increased by 13%−21%, and the increase is most obvious when the volume fraction of steel fiber is 1.0%. With the increase of steel fiber content, the deformation ability and ductility of the specimen are improved, and the ductility coefficient of the specimen reaches 5.34 when the volume fraction of steel fiber content is 2.0%. The intensity attenuation is slow, and the control displacement increases with the addition of steel fiber. In the case of large deformation, the intensity attenuation of the specimen decreases from 28% to 16% in condition of large deformation. The toughening effect of steel fiber can significantly improve the seismic performance of steel reinforced concrete composite structures.