预应力再生混凝土叠合梁受弯性能试验研究

为研究无黏结预应力再生混凝土叠合梁构件的受弯性能,以再生混凝土在叠合梁中的位置、叠合层高度、构件的配筋率为参数,对1根预应力普通混凝土整浇梁、1根预应力再生混凝土整浇梁和6根预应力再生混凝土叠合梁构件进行弯曲加载试验,分析了试验梁构件的受力过程和破坏形态,探讨了各参数对试验梁构件极限承载力的影响.基于试验数据,对承载力...

Experimental Study on Flexural Behavior of Prestressed Recycled Concrete Composite Beams

In order to study the flexural behavior of unbonded prestressed recycled concrete composite beam members, the position of recycled concrete in the composite beam, the height of the composite layer, and the reinforcement ratio of the members were taken as parameters, one prestressed ordinary concrete cast-in-place beam, one prestressed recycled concrete cast-in-place beam and six prestressed recycled concrete composite beam members were subjected to bending loading tests. The stress process and failure modes of the test beam members were analyzed, and the effects of various parameters on the ultimate bearing capacity of test beam members were discussed. Based on the experimental data, the bearing capacity of the unbonded prestressed recycled concrete composite beam under the ultimate bearing capacity state was verified. The results show that when recycled concrete is applied to the bending members of prestressed composite beam members, the strain change law along the height of the mid-span section is consistent with the assumption of the plane section, and there is a good interaction between ordinary concrete and recycled concrete, so they can cooperate to force and deformation. The stress increment curve of the unbonded prestressed steel strand is a three-fold line. When the recycled concrete is located in the precast layer, under the same condition of reinforcement, the increasing of the precast layer height will delay the tensile yield of the ordinary longitudinal stressed steel bars in the beam. With the same precast layer height, improving the strength of the longitudinal steel bars can effectively improve the performance of the beam. Compared with ordinary concrete beams, the number of cracks in recycled concrete beams is relatively large, and the crack extension height is relatively small when reaching the ultimate load. When the recycled concrete is located in the laminated layer, the number of cracks increases, and the crack spacing is relatively small. With the increases of precast layer height and member reinforcement ratio, the average crack spacing of test beams gradually increases.