رفتار لرزه ای و مقاومت برش ستون های فریم SRHC Research on seismic behavior and shear strength of SRHC frame columns

1 Introduction Earthquake investigations and experimental studies have verifi ed that the seismic behavior of steel reinforced concrete (SRC) structures is obviously better than that of reinforced concrete (RC) structures (Ji et al., 2015). For lower stories in high-rise buildings, the carrying capacity of a SRC frame column cannot satisfy the seismic demand due to the poor ductility arising from the small shear span ratio. Nevertheless, the SRHC frame column possesses signifi cant advantages. As an optimized combination of high-tech concrete material and new-style composite structures, steel reinforced high strength and high performance concrete (SRHC) structures possesses excellent mechanical performance and seismic behavior, and are being used more often in engineered structures. Zheng et al. (2011) discussed the damage evolution in steel reinforced high strength concrete (SRHSC) frame columns based on the test results of cyclic reversed loading experiments on 12 frame column specimens, which resulted in a damage model that can well refl ect the mechanical characteristics of SRHSC members subjected to horizontal earthquake action. Yan et al. (2010) investigated the seismic performance of a composite frame comprised of steel reinforced ultra high-strength concrete (SRUHSC) columns and steel reinforced concrete (SRC) beams. Lu et al. (2015) presented an experimental study on the compressive behavior of steel fi ber reinforced high strength concrete-fi lled steel tube columns. A new deck system for moveable bridges was developed that makes use of ultra-high performance concrete (UHPC) reinforced with high strength steel (HSS) rebars to achieve light weight and high strength requirements. Xia et al. (2011) investigated the mechanism of the deck strip shear failure experimentally and analytically. Kamal et al. (2014) aimed to evaluate the behavior of ultra-high strength concrete beams; a total of 12 simple concrete beams with and without shear reinforcements were tested in fl exure. Despite ongoing worldwide efforts to improve concrete, more thorough and systematic experimental research is needed on the seismic behavior of SRHC frame columns. This is especially true when the concrete strength grade exceeds C100 (Li et al., 2007a; Abed et al., 2013). Therefore, the column element between the points of infl ection of the frame structure was selected as a focal point, and the seismic behavior of 16 SRHC frame column specimens were studied from every aspect including their mechanical characteristics, failure mode, bearing capacity, hysteretic behavior, ductility and energy dissipation.