|Budget Amount *help
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2001: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2000: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1999: ¥1,400,000 (Direct Cost: ¥1,400,000)
In the Hyogo Nanbu earthquake 1995, A lot of Bridges were damaged greatly. To prevent the damage of bridges, a new structure which has excellent performances on the strength and the displacements should be developed.
It is well known that Concrete Filled steel Tube (CFT) has excellent mechanical performances. If the uniting of the steel tube and concrete will be promoted, the performance increases leaping. In this study, Reinforced Concrete Filled operation Between the steel Tube (RCFT) that Reinforced Concrete (RC) is filled in the steel tube, was treated. By experiments, the composite operation between the steel tube and RC, and mechanical performances by the rib were researched. Besides, it IB researched how the ratio of radius of cylinder to wall thickness, strength of filled concrete influence to the performance of RCFT.
In this study, compression tests and bending tests, related to CFT and RCFT, were carried out to investigate their mechanical properties. The findings obtained from the series of tests are as follows.
in Compression test
(1) Strength and ductility of CFT-RCFT specimens were more excellent than RC specimens.
(2) High strength concrete is excellent in the maximum strength. But, it is inferior to the ductility.
(3) The rib improves the strength and confined effect. And the ductility is excellent, too.
(4) The local buckling stiffened effect was excellent in the case of thin steel tubes.
in bending test
(1) In the strength and ductility factor, high strength CFT-RCFT were equal approxmately to low strength CFT・RCFT.
(2) The local buckling stiffened effect was excellent in the case of thin steel tubes.
(3)The rib improves the strength and confined effect of RCFT. And the ductility is excellent, too.