Grant-in-Aid for Scientific Research (A)
|Allocation Type||Single-year Grants |
|Research Institution||HOKKAIDO UNIVERSITY |
UEDA Tamon Hokkaido Univ., Graduate School of Eng., Associate Professor, 大学院・工学研究科, 助教授 (00151796)
HATTORI Atsushi Kyoto Univ., Graduate School of Eng., Research Associate, 大学院・工学研究科, 助手 (30243067)
MUTSUYOSHI Hiroshi Saitama Univ., Fac.of Eng., Professor, 埼玉大学・工学部, 教授 (60134334)
NAKAMURA Hikaru Yamanashi Univ., Fac.of Eng., Associate Professor, 山梨大学・工学部, 助教授 (60242616)
SATO Yasuhiko Hokkaido Univ., Graduate School of Eng., Research Associate, 大学院・工学研究科, 助手 (60261327)
SHIMURA Kazunori Hokkaido Univ., Graduate School of Eng., Research Associate, 大学院・工学研究科, 助手 (60187474)
|Project Period (FY)
1996 – 1997
Completed (Fiscal Year 1997)
|Budget Amount *help
¥9,400,000 (Direct Cost: ¥9,400,000)
Fiscal Year 1997: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 1996: ¥5,500,000 (Direct Cost: ¥5,500,000)
|Keywords||Strengthening / FRP Sheet / FRP tendon / Deformation of concrete members / Capacity of concrete members / 外ケーブル|
This study is carried out to develop the design method for strengthening of exsisting concrete structures using FRP sheets and FRP tendons. Results in this study are summarized on the following three points ; (1)Long term properties of reinforcing materials, (2)Ultimate capacity and deformation of concrete members retrofitted with FRP sheet, (3)Ultimate capacity and deformation of concrete structures retrofitted with FRP tendons.
(1) Long-term Properties of Reinforcing Materials
・The relaxation ratio represents the natural characteristics of each FRP tendon and varies in proportion to the logarithm of time throughout the entire loading time range.
・The tensile strength and bond strength of FRP sheet were not reduced even after FRP sheet is soaked in 10% sulfuric acid solution for six months.
(2) Ultimate Capacity of Deformation of Concrete Members Retrofitted with FRP Sheets
・It was clarified how concrete strength, and stiffness of FRP sheets affect the bond mechanism of FRP sheet. The bond strength equation was proposed.
・When peeling of FRP sheet which is attached to a lower face in a beam as flexural reinforcement does not occur, the bending capacity and deformation of the beam can be predicted by the layr-by-layr procedure.
・For failure mode with peeling of FRP sheet along a shear crack, the model of predicting the shear reinforcing effect of FRP sheet was proposed.
(3) Ultimate Capacity and Deformation of Concrete Structures Retrofitted with FRP Tendons
・The flexural behavior of externally prestressed beams can be estimated by a precise calculation method considering the compatibility of deformations and changes in location of cables.
・The ultimate strength of FRP tendons at deviators becomes less then the uniaxial tensile strength. The rate of reduction differs for different type of FRP tendons.
・When a cable tensile force was within the range of 40 to 50% of the nominal breaking load for AF rope, failure did not occur during the the 2,000,000-cycle loading.