预制–现浇复合梁抗弯性能试验研究

Experimental Study on Flexural Performance of Precast Cast-in-Place Composite Beams

摘要: 基于锚杆挡土墙装配化的需要，设计了一种由预制板和现浇混凝土构成的复合梁，通过四点弯曲试验测试了复合梁的抗弯承载力的特性，并分析了复合梁预制层的作用。主要结论有：弯矩作用下复合梁的破坏发生在预制板拼接处，其变形失效过程可分为弹性、带缝工作和破坏三阶段，最终破坏型式为拼接处的预制板一侧张开、另一侧压缩破坏；复合梁的实测极限承载力要明显高于由预制板拼接处有效截面尺寸计算的承载力理论值；预制板对提高梁承载力的作用主要源自两方面：一是约束了接缝截面两侧混凝土的变形，使梁只能沿接缝截面发生破坏，二是在复合梁受压侧预制板间的间隙会因芯梁压缩而消失并增加梁的受压区截面尺寸。

Abstract: A composite beam composed of prefabricated panels and cast-in-place concrete was designed based on the assembly needs of anchor retaining walls. The bending bearing capacity characteristics of the composite beam were tested through four point bending tests, and the role of the prefabricated layer of the composite beam was analyzed. The main conclusions are as follows: the failure of composite beams under bending moment occurs at the junction of prefabricated slabs, and its deformation failure process can be divided into three stages: elastic, jointed work, and failure. The final failure mode is the opening of one side of the prefabricated slab at the junction and the compression failure of the other side; the measured ultimate bearing capacity of composite beams is significantly higher than the theoretical value of bearing capacity calculated from the effective cross-sectional dimensions at the joints of prefabricated panels; the role of prefabricated panels in improving the bearing capacity of beams mainly comes from two aspects: firstly, it constrains the deformation of concrete on both sides of the joint section, so that the beam can only be damaged along the joint section; secondly, the gap between prefabricated panels on the compression side of the composite beam will disappear due to the compression of the core beam and increase the cross-sectional size of the compression zone of the beam.