装配式预应力混凝土框架梁柱压接接缝直剪试验

Direct shear test study on post-tensioned grouting connection of beam-to-column in precast prestressed concrete frame structures

为了研究预压应力、预应力分布、预应力筋销栓作用以及灌缝材料对装配式预应力混凝土框架梁柱压接接缝直剪性能的影响,进行了17个接缝试件的直剪试验,并提出了压接接缝直剪承载力的计算方法.结果表明,预应力能有效提高接缝的直剪承载力.接缝截面均匀受压时,接缝的极限剪应力与均匀预压应力之间呈1.235 6倍的线性正相关关系,接缝的残余剪应力与均匀预压应力之间呈0.706倍的线性正相关关系.接缝截面偏心受压时,其预应力分布对极限承载力存在明显影响,在相同的预加力作用下,预加力偏心距越大,极限承载力下降也越明显.接缝的极限承载力由黏结力和预加力产生的静摩擦力组成;接缝的残余承载力由压力产生的摩擦力和预应力筋的销栓作用组成.

To study the influence of the prestress, the distribution of prestress, the dowel action, and the filler material on the shear behaviors of the post-tensioned prestressed grouting connection in precast prestressed concrete frame structures, direct shear tests were carried out on 17 specimens. The calculation method of the shear strength of the post-tensioned prestressed grouting connection was proposed. The results show that post-tensioning can effectively increase the shear strength of the connections. When the post-tensioned prestressed grouting connection is under uniform prestress, there is a linear positive correlation of 1.235 6 times between the ultimate shear strength and the uniform prestress, and there is a linear positive correlation of 0.706 times between the residual shear strength and the uniform prestress. When the post-tensioned prestressed grouting connection is under eccentrical prestress, the prestress distribution has an obvious effect on the ultimate shear strength. When the post-tensioned prestressed grouting connection is under the same prestress, the greater the eccentricity of the resultant force, the greater the reduction in the ultimate shear strength of the connection. The ultimate shear strength of the connection is determined by the adhesion and the static friction, and the residual shear strength of the connection is composed of the friction generated by the pressure and the dowel action of embedded steel bars.