叠合梁斜截面抗剪性能的试验研究

Experimental research on the shearing resistance strength of oblique section of composite beam

通过对叠合模型梁的承载能力、梁的变形特征、裂缝的形成和发展过程以及梁中箍筋、纵筋应力变化情况的观测,得到了按斜截面抗剪强度设计的叠合梁的破坏过程,以及在这个过程中箍筋所起的影响作用.试验结果表明:参照整浇梁的理论计算方法,二次受力叠合梁的极限抗剪承载力比相应情况的整浇梁要略高,其中箍筋的实际有效作用比由规范公式[1]计算得出的理论贡献值要大;梁的变形特性以及裂缝开展情况与一般整浇梁很类似,其最终破坏形态也与一般整浇梁接近.试验成果为叠合梁的进一步研究和工程应用提供了有价值的实验依据.

Through observation of the bearing capacity of the composite pattern beams, the deformation behavior of the beams, the formation and developing process of the crack and the stress alteration of the hoop reinforcement and longitudinal reinforcement in beams, we obtain the destroy process of the composite beams according to the shearing resistance strength of the oblique section, and also the effect of the hoop reinforcement in this process. The result shows, by comparing with theoretical calculated value, the critical shearing resistance strength of secondary stressed composite beams is slightly higher than the wholly casting beams under the same condition, and the actual useful effect of the hoop reinforcement is larger than the theoretical calculated contribution value according to the equation of the code. Further more, through observation of the experimental process, the deformation behavior and the developing of the crack of the beams is similar to the general beams, and the ultimate breakdown conformation of composite beams also comes close to it of general wholly casting beams.