密拼叠合板拼缝构造及受力性能试验研究

Experimental Study on Joint Structure and Mechanical Performance of Densely Assembled Composite Slabs

为了研究拼缝构造对密拼预应力钢筋混凝土叠合板受力性能的影响,提出一种增强型密拼缝构造,并设计了3组叠合板试件的抗弯性能试验.试验对各组试件的承载能力、刚度、破坏形态、裂缝和变形性能进行系统性研究,并分析拼缝叠合板的拼缝传力性能和预应力叠合楼盖的双向受力特性.试验结果表明:增强型密拼缝连接能够提高叠合板的垂直拼缝方向的抗弯刚度,其承载能力接近于现浇板,同时能够保证拼缝处力的有效传递;拼缝板试件破坏时拼缝位置的裂缝形态较好,且未发生沿叠合面的撕裂破坏;预应力叠合单板的承载能力及变形性能均较好.预应力叠合楼盖的受力性能试验进一步表明:采用该种增强型拼缝构造的叠合板能够进行双向传力,基于虚功原理建立预应力叠合楼盖极限承载力公式,极限荷载计算值与试验值吻合较好,验证了假定的塑性铰线模式的合理性;利用条带法再次验证了预应力叠合楼盖的双向受力性能.

In order to study the effect of joint structure on the mechanical performance of densely assembled pre⁃stressed reinforced concrete composite slabs,an enhanced tight joint details is proposed,and the flexural tests of three groups of composite plates were designed.The test systematically studied the bearing capacity,stiffness,failure mode,crack and deformation performance of each group of specimens,and the joint force transmission performance of the jointed laminated slab as well as the two-way mechanical characteristics of the prestressed composite floor are analyzed.The test results show that the enhanced tight joint can improve the flexural stiffness of the composite slab in the vertical direction of the joint,its bearing capacity is close to that of the cast-in-place slab,and it can ensure the effective load transmission at the joint.The crack morphology at the joint position is good when the joint plate speci⁃men fails,and no tear damage occurs along the composite surface.The bearing capacity and deformation performance of the prestressed composite slabs are good.The mechanical performance test of the prestressed composite floor fur⁃ther shows that the composite slab with the reinforced joint structure can carry out two-way load transmission.An ul⁃timate bearing capacity formula of the prestressed composite floor was established based on the principle of virtual work.The calculated value of the ultimate load is good in agreement with the experimental value,which verifies the rationality of the assumed plastic hinge line mode.The strip method was used to verify the two-way mechanical per⁃formance of the prestressed composite floor.