| 種別 | paper |
| 主題 | An Experimental Study on the Tensile Capacity of Vertical Bar Joints in a Precast Shearwall |
| 副題 | |
| 筆頭著者 | Jose ADAJE（Graduate School, University of Tsukuba） |
| 連名者1 | Teruaki YAMAGUCHI（Technical Research Institute, Kabuki Construction CO.Ltd） |
| 連名者2 | Hiroshi IMAI（Institute of Engineering Mechanics, University of Tsukuba） |
| 連名者3 | |
| 連名者4 | |
| 連名者5 | |
| キーワード | |
| 巻 | 15 |
| 号 | 2 |
| 先頭ページ | 1255 |
| 末尾ページ | 1260 |
| 年度 | 1993 |
| 要旨 | INTRODUCTION Connections and detailings are the usual problems in precast shearwalls.In the conventional method, the joints are usually located at wall ends.This implies that both concrete and reinforcing bars are jointed at critical locations where,during the action of lateral loads,Iarge stresses occur.This research aims to establish a new,simple and economical technique of connecting vertical bars in precast concrete shearwalls at locations where seismic forces are less. In this technique,the precast concrete panels and the vertical reinforcements,which are separated in the fabrication plant,are connected at the site.Concrete joints are at member ends while vertical bar joints are at mid-height of the wall. As a pioneering research,the tensile capacity of the newly developed method of connection is investigated. CONCLUSION The following conclusions were drawn from the experiment.1) In vertical bar joints with corrugated steel sheath,the failure modes are: bond failure around the sheath and direct pullout of main bar.2) A direct pullout of main bar occurs when the splice length is more than 25d,that is when there is an adequate lateral confinement.3 )A bond failure around the sheath can be assumed when the grout resisitance inside the sheath exceeds the lateral confinement of splicing.4) With a constant total cross sectional area,splice bars with larger diameter provide greater strength due to an increase in the splice length.5) At a splice length more than 25d,the bar joint capacity remains almost equal to the tensile strength of main bar. 6) A change from 200 mm spacing of main bars to 300 mm gives large increase in the joint capacity but a change from 300 mm to 400 mm provides slight increase in the capacity.7) A lug height of more 2.0 mm has a strength almost equal to that of 2.0 mm.8) A decrease in spiral pitch improves the structural performance of the bar connection.9) 10 repetitions of cyclic loads have no effect on the structural performance of the joint.10) Orangun,Jirsa,and Breen's equation can be used to roughly estimate the bond strengths of main bar and steel sheath. |
| PDFファイル名 | 015-01-2212.pdf |