Experimental study on seismic behavior of composite frame consisting of SRC beams and SRUHSC columns subjected to cyclic loading

摘要

The seismic behavior of steel reinforced ultra-high strength concrete (SRUHSC) and steel reinforced normal-strength concrete (SRNSC) frames is experimentally investigated in this paper. For this purpose, two one-fourth scale, 2-bay, 3-story specimens were designed and constructed. Two specimens were tested subjected to low reversed cyclic loading using MTS loading system. In terms of loading displacement hysteretic curves, lateral load carrying capacity, displacement ductility, energy dissipation, stiffness, and strength degradation, etc, the seismic behavior of SRUHSC and SRNSC frame specimens are investigated under low reversed cycle lateral loading. The experimental results show that the beam hinge failure mechanism is achieved by the two frames. Even if subjected to large axial load with an axial loading ratio of 0.38, they are able to exhibit the plump hysteretic load-displacement curves without obvious pinching phenomenon. Meanwhile, the top and story ductility coefficients of two frames are both overtake 3.0, which showed that the specimens have excellent seismic behavior with sufficient ductility. However, in terms of carrying capacity, displacement ductility coefficient, hysteretic load-displacement curves area, strength, and stiffness degeneration, etc., SRNSC frame is totally weaker than SRUHSC frame. The results obtained indicate that adopting encasing structural steel and high-strength stirrups into the ultra-high strength concrete is a good way for alleviating the problem of brittleness and improving structural carrying capacity by significantly making use of the compressive high strength property and enhancing the structural ductility. Therefore, the seismic behavior of SRUHSC frame is better than that of SRNSC frame. (C) 2016 Elsevier Ltd. All rights reserved.