| 種別 | paper |
| 主題 | Experimental Investigation of External Prestressed Con-crete Beams |
| 副題 | |
| 筆頭著者 | Songkiat MATUPAYONT（Graduate School of Engineering, Saitama Universty） |
| 連名者1 | Hiroshi MUTSUYOSHI（Departuent of Civil Engineering, Saitama Universty） |
| 連名者2 | Atsuhiko MACHIDA（Departuent of Civil Engineering, Saitama Universty） |
| 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 | 1285 |
| 末尾ページ | 1290 |
| 年度 | 1993 |
| 要旨 | INTRODUCIION External prestressed concrete beams have been extensively developed for the new trends of consruction during the past ten years, especially in Europe, due to some advantages of PC beam using external cable system such as,1)dead load of structures can be reduced by making web thickness smaller.2)old or damaged cables can be easily replaced and/or re-prestressed,3)loss due to friction of tendon can be reduced,etc.To determine the ultimate bending capacity of external PC beam,the stresses in cable at ultimate have to be computed.An accurate calculation for the stress in cable of unbonded members at ultimate state is more difficult than for that of bonded ones.A lot of previous analytical and experimental studies have been undertaken to investigate the stresses in the cable of PC beams.These studies implied that an external PC beam can be treated as an unbonded member due to non-bonding between concrete and cables.The purposes of this paper are,1)to study the ultimate behavior of PC beam using different materials for external cables,which were prestressing steel (swrR7B/12.7 mm),AF-rope (Aramid Fiber rope without resin) and CFRPll7.8 mm(Carbon Fiber Reinforced Plastics tendon combined with resin),2)to review the existing prediction equations for the cable stress at ultimate state proposed by the previous investigators,so that the equations with good accuracy can be determined,and 3)to compare the test results obtained in this study with the value computed by the selected equations.In addition,the applicability of the prediction equation to PC beam using new materials as external cable was checked. CONCLUSION External PC beams using various kind of materials as external cables were experimentally investigated.Three specimens having prestressing steel,AF-rope and CFRP as external cables were tested.The existing studies were reviewed in order to obtain the prediction equations for stress in cable with acceptable accuracy.From the test results and study reviews,the conclusions can be drawn as the following；・From load-deflection curves,test specimens having different material as external cables give almost the same ultimate flexural behavior.・It can be noted that the new materials are acceptable for use as external cables for PC beam.However,the brittle material,such as CFRP,must be carefully used for the design purposes when it is arranged in curved line or sharp bend. The review of existing studies (six studies) disclosed that Naaman's proposed equation gave the better accuracy than those of the other studies.・The prediction equations selected in this study gave a poor accuracy of predicted value for PC beam using AFRP-rope and CFRP cable as the external cables. However,to confirm the applicability of those equations,further studies should be done. |
| PDFファイル名 | 015-01-2217.pdf |