| 種別 | paper |
| 主題 | An Experimental Study on Joint Strength of Spliced Bars for Precast Concrete Structures |
| 副題 | |
| 筆頭著者 | Rodolfo YANEZ（Doctoral Degree Program, University of Tsukuba） |
| 連名者1 | KenTABATA（Undergraduate Student, University of Tsukuba） |
| 連名者2 | Teruaki YAMAGUCHI（Technical Research Institute, Kabuki Construction Co. Ltd.） |
| 連名者3 | Hiroshi IMAI（Institute of Engineering Mechanics, University of Tsukuba） |
| 連名者4 | |
| 連名者5 | |
| キーワード | |
| 巻 | 15 |
| 号 | 2 |
| 先頭ページ | 1261 |
| 末尾ページ | 1266 |
| 年度 | 1993 |
| 要旨 | INTRODUCUON During an earthquake,the stresses at the end of the structural members become larger,therefore it is desirable for the bar joints of Precast Concrete (PCa) structures to be placed at the less stressed portion of beams and columns,to ensure satisfactory strength and ductility against seismic forces.The bar joint method proposed by Imai et.al.was proved to be good enough to transfer the stresses from each bar to the surrounding concrete matrix.However,it is a fact that as the bar diameter increases the resistant surface of concrete to the splitting force becomes smaller and the bond strength decreases.In the proposed system a steel sheath with diameters of 42mm has been used for bars of 25mm,then the feasibility of this system should be studied through the bond strength of this lapping joint splice.In this paper,an experimental study on the strength of different types of bar joints is reported.Test results on main bar joints for PCa structures are compared with those for cast in situ ones.The influence on the strength when one lapping bar with the same section to the main bar is used instead of two bars,is also studied.Test results are compared with the existing equations for spliced bars. CONCLUSIONS From the foregoing discussions, the following conclusions can be obtained.1) The load for the initial bending cracks can be predicted with good accuracy based on the assumption that plane section remains plane after deformation.2) A better performance for the bottom bars than for the top bars is recognized.3) Splice types A, B, C and D showed almost the same strength for either the top or bottom bars,while splice Types F and G presented lower strength than C.4) No influence of the eccentricity of the bar with respect to the sheath axis is recognized.5) A better performance of the spliced joint could be expected if one main bar is spliced with two lapping bars instead of one lapping bar.6) The test results showed good agreement with the calculated values by the Orangun-Jirsa-Breen equation.7) Specimen with splice types A or B and lateral reinforcement with a pitch of 100mm,showed a better performance in either the top or bottom bars than other specimens. |
| PDFファイル名 | 015-01-2213.pdf |