全尺寸复合楼板的试验
Dennis Lam , Xianghe Dai , Therese Sheehan
工程(英文) ›› 2019, Vol. 5 ›› Issue (2) : 223 -233.
全尺寸复合楼板的试验
Testing of a full-scale composite floor plate
为了研究楼板在复合梁的格栅中的弯曲性能以及面内效应,我们对一种全尺寸复合楼板进行了试验,以降低混凝土板沿主梁线纵向开裂的趋势。在钢板定向平行于梁却不并排放置的情况下,这样的改变非常重要。在这种情况下,重要的是证明从剪切连接件中传递的局部力,以及与欧洲规范4 相比,其所需的横向钢筋量有所减少。研究机制涉及混凝土板产生的面内压缩力,这是由于楼板受到外围的复合梁支撑产生了约束作用;而次梁作为横向纽带用于抵抗楼板中的作用力,否则会导致混凝土板沿主梁线分裂。我们对主梁中心线及外围梁的开裂趋势进行了精密测试,这是自20世纪90年代初卡丁顿试验以来,在实验室条件下进行的第一次大型楼板试验,虽说卡丁顿试验并没有失败。这次楼板试验的目的是即使主梁传递的纵向力相对较高(即设计为全剪切连接件),但混凝土面层中钢筋最小配筋率仅为0.2%。该试验证实,尽管在钢板不连续,以及使用欧洲规范4中规定的横向分布钢筋最小配筋率的情况下,主梁仍然达到了其塑性抗弯性能。在此基础上,我们提出了无 U 形钢筋(U-bars)的边梁剪切连接件的折减系数。
A full-scale composite floor plate was tested to investigate the flexural behavior and in-plane effects of the floor slab in a grillage of composite beams that reduces the tendency for longitudinal splitting of the concrete slab along the line of the primary beams. This is important in cases where the steel decking is discontinuous when it is orientated parallel to the beams. In this case, it is important to demonstrate that the amount of transverse reinforcement required to transfer local forces from the shear connectors can be reduced relative to the requirements of Eurocode 4. The mechanism under study involved in-plane compression forces being developed in the slab due to the restraining action of the floor plate, which was held in position by the peripheral composite beams; while the secondary beams acted as transverse ties to resist the forces in the floor plate that would otherwise lead to splitting of the slab along the line of the primary beams. The tendency for cracking along the center line of the primary beam and at the peripheral beams was closely monitored. This is the first large floor plate test that has been carried out under laboratory conditions since the Cardington tests in the early 1990s, although those tests were not carried out to failure. This floor plate test was designed so that the longitudinal force transferred by the primary beams was relatively high (i.e., it was designed for full shear connection), but the transverse reinforcement was taken as the minimum of 0.2% of the concrete area. The test confirmed that the primary beams reached their plastic bending resistance despite the discontinuous decking and transverse reinforcement at the minimum percentage given in Eurocode 4. Based on this test, a reduction factor due to shear connectors at edge beams without U-bars is proposed.
楼板试验 / 复合梁 / 边梁 / 欧洲规范4 / 面内效应 / 柱移除 / 坚固性
Floor plate test / Composite beams / Edge beams / Eurocode 4 / In-plane effect / Column removal / Robustness
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