Study on Development of Steel-Free Concrete Deck Slabs

无钢混凝土楼承板的开发研究

基本信息

批准号：
11555114
负责人：
KAWAKAMI Makoto
金额：
$ 3.33万
依托单位：
Akita University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

(1)First series of loading tests for steel-free slabs were carried out to clarify ultimate strength and deflection. In these tests, the thickness and width of steel plate used to confine the concrete slabs were considered as variable parameter. From these tests results, the increase of confinement ratio has drastically influenced the change of failure mode from bending to shear failure. However higher confinement ratios than 2% have not increased the strength significantly.(2)Effect of the end supports condition and prestressing on the flexural behavior of steel-free slab by undergoing an experimental and theoretical study on a simple supported and fixed slabs in both prestressed and non-prestressed cases were investigated. The results obtained from the second series of tests can be summarized as follows ; 1)End support confinement is efficient in restraining the steel-free slabs before cracking, but it is not reliable after cracking. 2)External prestressing is effective in increasing both cracking and ultimate loads.(3)Third series of load tests are punching tests on six full scale steel-free slabs transversely prestressed with unbonded external bars. The obtained results showed that unbonded prestressing and concrete strength increased the ultimate punching load to some extent but no considerable effect on increasing the cracking load was obtained. Prestressing proved efficiency in controlling cracks development, which means a great improvement on the serviceability of the slab.(4)All results of two years from 1999 to 2001 were summarized and the report was completed.

（1）进行了无钢板的第一级加载测试，以阐明最终的强度和偏转。在这些测试中，用于限制混凝土板的钢板的厚度和宽度被认为是可变参数。从这些测试结果中，限制比的增加极大地影响了失败模式从弯曲到剪切失败的变化。但是，高于2％的限制率高于2％的强度。（2）通过对两者的简单支持和固定平板进行实验性和理论研究，终端的影响支持条件和预应力对无钢板的弯曲行为。调查了预应力和未预先认可的病例。从第二系列测试中获得的结果可以总结如下。 1）最终支撑限制在破裂之前在限制无钢板方面是有效的，但是破裂后不可靠。 2）外部预应力可有效增加开裂和最终负载。（3）第三系列负载测试是对六个全尺度无钢板进行打孔测试，该平板被未粘附的外部杆横向换句话。获得的结果表明，未粘附的预应力和具体强度在某种程度上增加了最终的冲压载荷，但对增加裂纹载荷没有相当大的影响。预应力证明在控制裂缝发展方面具有效率，这意味着对板的可维修性有了很大的改善。（4）总结了从1999年到2001年两年的所有结果，并完成了报告。