Research on Application of Steel-Concrete Composite Members filled with Rigid Urethane to Structures

钢-混凝土组合构件以轻质氨基甲酸酯代替受拉侧混凝土，在低高度桥梁中得到有效应用，有助于减轻桥梁自重。然而，低高度桥梁往往容易发生振动。在研究的第一阶段(2003年)，我们对三座钢-混凝土组合板桥进行了振动测试，其中两座填充硬质氨纶，一座完全填充混凝土。试验结果表明，刚性氨基甲酸酯可以提高桥梁的阻尼率50%以上。在第二阶段(2004-2005年)，我们验证了刚性氨基甲酸酯加固钢板的振动性能，因为我们认为在钢板上粘贴刚性聚氨酯可以降低桥梁的噪声。对不同厚度的氨基甲酸酯钢板进行了两种振动试验(冲击载荷试验和振动台振动试验)。冲击载荷试验：在3 mm厚、150 mm厚的氨基甲酸酯钢板上投掷高尔夫球，以检查高频段的振动，其阻尼比接近。与不含氨基甲酸酯的钢板相比，增加了4倍。当我们在上面的板上扔一个垒球来检查低频区的振动时，阻尼比大约是。在振动台上进行的振动试验：另一方面，证实了在振动台上用刚性聚氨酯振动钢板时，在钢板上粘贴聚氨酯可以增加钢板的加速度响应。

Steel-concrete composite member, the tension side concrete of which is replaced with light weight urethane, is used efficiently in low height bridges because it helps to reduce bridge weight. However, low height bridges tend to vibrate easily. In the first stage of the research (in 2003), we verified the effect of urethane, performing vibration tests on three steel-concrete composite slab bridges ; two filled with rigid urethane and one filled completely with concrete. The test result showed that rigid urethane increases damping ratio by more than 50 percent.In the second stage (in 2004-2005), we verified vibration property of steel plates with rigid urethane because we thought that rigid urethane attached to steel plates could reduce noise from the bridge. We performed two kinds of vibration tests (impact loading test and vibration test on a shaking table) on steel plates with various urethane thickness.Impact loading test : When we dropped a golf ball on a 3mm-thick steel plate with 150mm-thick urethane to check vibration in high-frequency region, damping ratio was approx. 4 times comparing a steel plate without urethane. When we dropped a softball on the above plate to check vibration in low-frequency region, damping ratio was approx. 2 times.Vibration test on a shaking table : On the other hand, it was confirmed that attaching urethane to steel plates increases the acceleration response of steel plates when vibrating steel plates with rigid urethane on a shaking table.