新型上部纵筋外置预制叠合梁抗弯性能研究

Bending Performance of Novel Prefabricated Reinforced Concrete Composite Beams with Externally Placed Upper Longitudinal Bars

摘要:

目前在工厂中制作钢筋混凝土叠合梁时通常不会将上部纵筋直接绑扎到钢筋笼中，而是在施工现场将上部纵筋穿入钢筋笼再进行绑扎，这使得上部纵筋施工难度大、效率低。针对此问题，提出了一种将上部纵筋直接放置于箍筋上方进行绑扎的连接构造，并设计了有凹槽和无凹槽两种箍筋形式。对尺寸、混凝土标号和配筋完全相同的现浇梁、传统预制叠合梁和新型上部纵筋外置预制叠合梁进行了受弯加载试验，然后使用ABAQUS软件对试验进行了数值模拟，研究了新型绑扎方式对梁力学性能的影响。结果表明，新型预制叠合梁与传统预制叠合梁的承载能力相同，略低于现浇梁，说明所提出的上部纵筋绑扎方式安全可靠，在实际工程中具有一定的应用前景。

Abstract:

Currently， when prefabricating reinforced concrete composite beams in factories， the upper longitudinal bars are typically not directly tied into the rebar cage. Instead， the upper longitudinal bars are passed through the cage and tied on-site， which makes the construction process more difficult and less efficient. To address this issue， this paper proposed a connection design where the upper longitudinal bars were directly placed above the hoop and tied. Two types of hoops were designed： one with a groove and one without. Bending tests were conducted on cast-in-place beams， traditional prefabricated composite beams， and the novel prefabricated composite beams with externally placed upper longitudinal bars， all of which had identical dimensions， concrete grades， and reinforcement configurations. Numerical simulations of the tests were performed using ABAQUS software to investigate the influence of the new tying method on the mechanical properties of the beams. The results indicate that the novel prefabricated composite beams exhibit similar load-bearing capacity to traditional prefabricated composite beams， slightly lower than that of cast-in-place beams. This suggests that the proposed method of tying the upper longitudinal bars is safe and reliable， with promising potential for practical application in engineering.