细晶粒钢筋混凝土柱偏心受压性能试验研究

EXPERIMENTAL STUDY ON REINFORCED CONCRETE COLUMNS WITH FINE GRAIN STEEL BARS UNDER ECCENTRIC COMPRESSION

对9根400 MPa级细晶粒钢筋混凝土柱开展偏心受压性能试验,研究轴向力偏心距、纵向受压钢筋配筋率、混凝土强度和长细比对柱偏心受压性能的影响,描述各试件的破坏过程,分析了其荷载-钢筋/混凝土应变曲线、荷载-挠度曲线以及破坏形态的特点。研究表明,现行混凝土结构设计规范关于钢筋混凝土偏心受压柱极限承载力、平均裂缝间距和最大裂缝宽度的计算理论与试验吻合较好。400 MPa级细晶粒钢筋屈服强度设计值取为360 MPa时,细晶粒钢筋混凝土偏压柱承载力具有足够的安全系数并偏向于保守。正常使用极限状态下,400 MPa级细晶粒钢筋混凝土大偏心受压柱在短期荷载作用下的最大裂缝宽度满足要求。

The tests of nine concrete columns reinforced with fine grain steel bars under eccentric compression were made, the effects of experimental parameters such as eccentricity distance , longitudinal compressive reinforcement ratio, concrete strength and slenderness ratio on their compression performance were studied .Components ’ failure processes were described;load-strain curves of concrete and steel bars and load-deformation curves were analyzed . Experimental results show that theoretic values of eccentric RC column ultimate bearing capacity , average crack spacing and maximal crack width calculated by current code for design of concrete structures are in accordance well with the experimental values .Bearing capacities of eccentric RC columns reinforced with HRBF 400 have enough safety factors and tends to conservatively while the yield strength of HRBF 400 was considered as 360 MPa.Under normal service state , maximal crack widths of large compression columns under shot-term load meet the requirement of the current code .