Grant-in-Aid for Developmental Scientific Research.
|Research Institution||Tohoku Univ.|
MIURA Takashi Tohoku Univ. Dept. Civil Engineering, Prof., 工学部, 教授 (90005512)
斉藤 裕 東北電力総合研究所, 研究員
氏家 久芳 東北電力(株), 電力技術研究所, 室長
HORI Muneo Tohoku Univ. Dept. Civil Engineering, Lect., 工学部, 講師 (00219205)
コバッチ フェレンス 東北大学, 工学部, 助手 (20215205)
ITABSHI Hirofusa Tohoku Univ. Dept. Civil Engineering, Assoc. Research, 工学部, 助手 (80142206)
斎藤 裕 東北電力(株), 電力技術研究所, 研究員
李 道憲 東北大学, 工学部, 助手
季 道憲 東北大学, 工学部, 助手
LEE Do Heun Tohoku Univ. Dept. Civil Engineering, Assoc. Research
UJI-IE Hisayoshi Tohoku Denryoku K. K., General Research Center, Head of the Concrete Dept.
SAITHO Yutaka Tohoku Denryoku K. K., General Research Center, Researcher
|Project Fiscal Year
1989 – 1991
Completed(Fiscal Year 1991)
|Budget Amount *help
¥10,500,000 (Direct Cost : ¥10,500,000)
Fiscal Year 1991 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1990 : ¥2,400,000 (Direct Cost : ¥2,400,000)
Fiscal Year 1989 : ¥6,300,000 (Direct Cost : ¥6,300,000)
|Keywords||Very Low Temp / Reinforced Concrete / Reinforcing Bar / Shock / Low-Temp. Brittleness / 極低温 / 鉄筋コンクリ-ト / 鉄筋 / 衝撃 / 低温ぜい性|
At very low temperatures concrete becomes stronger and harder than at ordinary temperature, so that when cracking occurs in the tension region of a reinforced concrete member it causes a great impact. On the other hand, since reinforcing steel bars also become more brittlear very low temeratures, it also sometimes occurs that the impact causes the failure of reinforcing bars the concrete members, especially at the bended parts of reinforcement. From the study it can be concluded as follows.
1. At very low temperatures concrete splits with a much bigger impact than at normal temperatures.
2. The strain and straining rate of the reinforcement due to the impact caused by the splitting of concrete are influenced by the radius of bending, the reinforcement ratio and so on.
3. The possibility of brittle failure of a reinforcing bar depends on the properties of the bar at that state, that is, on the kind of reinforcing bar, on the amount of could working, and so on.
4. When we design a reinforced concrete structure which is to be used at very low temperatures, it is necessary to take into consideration the impact resistibility of the reinforcement applied and make the limit of degree of cold working.