種別 | Paper |
主題 | EFFECT OF THE AMOUNT OF SHEAR REINFORCEMENT AND AXIAL FORCE ON THE ULTIMATE SHEAR STRENGTH OF RC COLUMNS |
副題 | |
筆頭著者 | Tetsumitsu EIGAWA |
連名者1 | Seiji KOKUSHO |
連名者2 | Yasuhiro MATSUZAKI |
連名者3 | Katsumi KOBAYASHI |
連名者4 | |
連名者5 | |
キーワード | |
巻 | 9 |
号 | 2 |
先頭ページ | 705 |
末尾ページ | 710 |
年度 | 1987 |
要旨 | 1.INTRODUCTION Recently, deformed high strength steel bar (ULBON) has been used in engineering field widely as shear reinforcement of reinforced concrete beams and columns, especially in high-rise reinforced concrete buildings. This kind of steel can be shaped in circular, rectangular and square spiral automatically by cold work according to design requirement. In order to utilize further this high strength steel for structural design effectively, series of RC beams with combination of high strength concrete had been tested (1). The relation between the ultimate shear strength Τu and the product of Pw and wσy (Pw: shear reinforcement ratio, wσy: yield strength of shear reinforcement) is given in Fig.1. As shown in the figure, in the range of high Pw・wσy the shear reinforcement did not yield and the failure mode was shear compression of concrete. It is expected that the shear compression failure mode will occur easily in case that the compressive axial force is applied. Therefore the objective of this experimental study reported here is to investigate the effects of the amount of shear reinforcement and axial force on the ultimate shear strength of RC columns with the high strength shear reinforcement. 4. CONCLUSIONS (1) In the range of low Pw・wσy, shear reinforcement develops to yield at the stage of shear failure, while in the range of high Pw・wσy, shear compression failure of concrete precedes the yielding of shear reinforcement. However, it is also observed that the range of Pw・wσy becomes narrow in which shear reinforcement develop to yield at the stage of shear failure as the compressive axial force increases. (2) In case that shear reinforcement develop to yield, the ultimate shear strength in creases with increasing of the compressive axial force. On the contrary, in case that the shear reinforcement does not develop to yield, shear compression failure occurs, and the ultimate shear strength of column tends to decrease as the compressive axial force increases. (3) In case of the presence of compressive axial force, the ultimate shear strength is strongly affected by the value of Pw・wσy as well as the amount of σo. |
PDFファイル名 | 009-01-2121.pdf |