新型预制预应力混凝土梁装配框架节点受弯试验研究

EXPERIMENTAL INVESTIGATION ON FLEXURAL BEHAVIOR OF INNOVATIVE CONCRETE FRAME JOINT ASSEMBLED WITH PRECAST PRESTRESSED CONCRETE BEAM

对4个十字形梁柱节点试件分别进行了正、负弯矩作用下的受力全过程试验,考虑不同套管布置应力释放方案对节点性能的影响,结合GB 50010—2010《混凝土结构设计规范》分析计算构件的受弯极限承载力、裂缝和挠度。结果表明:此体系节点的承载能力基本与现浇结构相当。正常使用荷载作用下最大裂缝宽度和加载点挠度值的理论计算结果与试验值一致,均能满足GB 50010—2010要求。梁端加设套管能有效减小梁顶混凝土的应力峰值,提高其抗裂性能,在满足预拉区梁顶混凝土不开裂的情况下,应力释放的套管布置越少越好。

All course loading tests of four cross-shaped beam-column joints specimens were conducted under the positive or negative bending moment. Diverse layouts of PVC sleeve were considered as an impact on the joint performance. According to the current design code,ultimate bearing capacity,maximum crack width and deflection were calculated,and the results showed that the flexural bearing capacity of a precast joint was basically the same as that of a cast-in-situ joint. In serviceability limit state,the experimental results of maximum crack width and deformability agreed with those of the calculation, and they both could satisfy the design specifications. The arrangement of sleeves at the beam end could effectively reduce the stress peak on the top of beam and improve the anti-cracking property. It is considered that fewer sleeves would be better if there was no crack of concrete on beam top in the pretensioned zone.