采用群栓钉的装配式组合梁抗弯性能试验研究

Experimental investigation on flexural performance of prefabricated composite beams with group studs

设计3根采用群栓钉的装配式组合梁并对其在正弯矩作用下的抗弯性能开展试验研究。结果表明:3根组合梁试件最终均发生了弯曲破坏;采用群栓钉的装配式组合梁试件具有良好的变形能力,且位移延性系数不小于3.7;较低的抗剪连接程度导致装配式组合梁的极限抗弯承载力和极限变形能力有不同程度的降低;在最终破坏发生时,预制混凝土板上预留孔与后浇混凝土的交界面处未发生压碎、剥离等破坏,组合梁的跨中挠度至少为梁跨度的0.89%。最后,基于试验结果探讨现行《钢结构设计标准》(GB 50017—2017)中的组合梁抗弯承载力计算公式用于评估采用群栓钉的装配式组合梁抗弯承载力的可行性。

Three prefabricated steel-concrete composite beams with studs arranged in groups are fabricated and tested under positive bending moment to investigate their flexural performance.The experimental results indicate that the flexural failure finally occurrs for the three beams;the prefabricated composite beams with group studs exhibite good deformability,and the displacement ductility coefficients are no less than 3.7.Decreasing the shear connection degree resulted in different levels of reduction in the ultimate flexural capacity and deformability of the prefabricated composite beams.No crushing or debonding is observed at the interfaces of the preformed holes in the precast concrete slabs and the post-cast concrete at the final failure;meanwhile,the mid-span deformation of the composite beams is at least 0.89%of the beam span.Finally,the feasibility of using the formula specified by the current standard for design of steel structures,GB 50017-2017,to evaluate the flexural resistance of prefabricated composite beams is discussed.