Research on the Application of Newly Developed Prestressed Concrete Structures

考虑到在桥梁上的应用，对新开发的预应力混凝土结构的实际应用进行了研究。将超高强度纤维增强混凝土（UFC）应用于PC梁腹板部分，实现了具有高强度和耐久性的优良组合结构。在2003年的基础研究中，发现了剪力键和钢筋穿透的应用是有效的，并证实了PC梁边缘的短段也是非常有效的止滑。2004年，在2003年所学知识的基础上，制作了预应力混凝土梁的试件。实际上，2004年对各种形状的腹板构件进行了检查，如矩形板、三角形板、桁架构件或预应力桁架构件。通过试验和非线性有限元数值分析，验证了结构的刚度、变形能力和极限承载力。通过这些试验，新开发的以UFC为腹板构件的PC结构表现出优异的力学性能。特别是，当使用矩形面板时，三角面板或桁架构件的容量是其两倍以上。预应力对桁架构件的作用也非常有效。综上所述，新开发的PC结构，即以UFC构件为腹板的PC梁，被证实可以创建安全可靠的土木工程结构。本研究成果发表在《材料、混凝土结构与路面学报》、《日本混凝土学会学报》等刊物上。

Giving a mind to the application to bridges, the practical use of newly developed PC structures has been investigated. The ultra-high strength fiber reinforced concrete (UFC) was used to the web part of PC girders to achieve the excellent composite structures having high strength and durability. From the basic research done in 2003, the application of the shear key and the penetration of reinforcing bars were found to be effective and it was confirmed that the stub at the edge of a PC girder was also very effective to stop the slip. In 2004, the specimens of PC girders were produced based on the obtained knowledge in 2003. Actually, various shapes of web members were examined in 2004, such as rectangular panels, triangular panels, truss members or truss members with prestress. By experiments and numerical analyses using nonlinear FEM, the stiffness, deformation ability and ultimate capacity were verified.According to these examination, the newly developed PC structures using UFC as web members have indicated the excellent mechanical behavior. Especially, when rectangular panels were used, the capacity was more than double for the case of triangular panels or truss members. The effect of prestressing for truss members was also very effective.In conclusion, the newly developed PC structures, i.e., PC girders having UFC members as web, were confirmed to create safe and sound civil engineering structures. The obtained results of this research were presented in various journals, such as Journal of Material, Concrete Structures and Pavement of JSCE, and the Proceeding of Japan Concrete Institutes.