钢筋混凝土T型叠合梁抗震性能试验研究

研究了由倒T型预制梁、预制板和现浇板组成的钢筋混凝土T型叠合梁。开展了低周反复荷载下叠合梁与现浇对比梁的足尺模型试验,对其破坏形态、滞回曲线、位移延性、刚度退化与耗能等进行了较系统的研究。研究表明:低周反复荷载下叠合梁与现浇梁均发生了受弯破坏;峰值荷载下,叠合梁中实测的预制梁与预制板之间和靠近腹板侧预制板与现浇板之间的滑移分别为0.5mm和0.2mm;叠合梁与现浇梁的滞回曲线前期均较饱满,后期表现出一定的捏拢,但总体耗能均较好;反复荷载下叠合梁的刚度退化主要发生在开裂至屈服阶段,屈服后其刚度退化较缓慢;叠合梁的正、负弯矩截面受弯承载力分别较现浇梁的低9%和3%左右;叠合梁的正、反向位移延性分别比现浇对比梁约低6%和14%,但2个试件的位移延性系数均大于4.8。此外,还对低周反复荷载下与单调荷载下试件的受力性能进行了对比与分析。

Experimental study on seismic behavior of reinforced concrete composite T-beams

The reinforced concrete composite T-beam which is composed of precast inverted T-beam,precast slAbs and cast-in-place(CIP) slab,is studied in this paper.Based on the low reversed cyclic loading tests on a full-scale composite beam and the CIP control specimen,the failure mode,hysteresis curves,displacement ductility,stiffness degradation and energy dissipation capacity etc.were investigated.The results indicated that both the composite beam and the CIP control specimen failed in bending.The measured slips between precast beam and precast slab and between precast slab and CIP slab near the web were 0.5mm and 0.2mm under the peak load,respectively.Both specimens exhibited a stable load-deflection hysteresis response at the low deflection levels,and slight pinching could be noticed in the hysteresis loops at higher deflection levels,however,the overall energy dissipation capacity of the specimens was good.The stiffness of composite beam degraded evidently from cracking to yielding,while the stiffness degradation became relatively slow after yielding.The positive and negative flexural strength of normal section of composite beam was about 9% and 3% lower than those of the CIP control specimen,respectively.The displacement ductility of composite beam was approximately 6% and 14% lower than those of the CIP specimen in the positive and negative directions respectively;however,the displacement ductility factor of both specimens was more than 4.8.In addition,the behavior of composite beam and the CIP control specimen under cyclic loading was compared with those of the corresponding specimens under monotonic loading.