摘要
传统的弯起器受到结构尺寸与构造要求的限制,起弯点导向半径R较小,预应力筋将在起弯点形成"折点",产生严重的应力集中现象从而影响先张梁的整体力学性能,同时对钢绞线力学性能产生较大折减,严重降低结构在施工与使用中的安全性。本文基于现有弯起器存在的不足,通过对传统滚轴式弯起器进行优化改良,提出采用扁平导向构件代替园形截面导向辊的构想;并设计了详细的试验方案,以研究不同导向半径R与弯折角度θ的弯起器对钢绞线极限抗拉强度、延性性能及弯折摩阻预应力损失的影响规律,验证新型弯起器的优越性,该试验将为折线配筋先张梁的深入分析与研究提供一定帮助与参考。
In the prestressed reinforced concrete structures,there is usually stress concentration in the fold points along prestressed reinforcements.Excessive stress brings destruction to the concrete near the fold point,which greatly affects the normal use,and must be improved by developing new transfer apparatus.With theoretical analysis and experiments,this kind transfer apparatus turns to be of significant use in improving the phenomenon of stress concentration.Besides,the influence by using the transfer apparatus on prestressed reinforcement needs to be considered and studied.The scheme in this paper is that the prestressed reinforcements are arranged like that in beam using the special transfer apparatus which is only for testing the performance and ultimate strength of prestressed reinforcements and has been made before,and then analysis the effects on prestressed reinforcements by changing marking forming angle and crooked process radius through tension tests.In order to embody the superiority of the new transfer apparatus in playing mechanical performance of prestressed reinforcements,the new transfer apparatus needs to compare with the traditional one in the influence on the mechanical performance of prestressed reinforcements.
出处
《四川建材》
2012年第2期42-44,共3页
Sichuan Building Materials
基金
住房和城乡建设部科学技术项目计划(2011-K2-23)
湖北省教育厅科学技术研究项目(Q20111314)
长江大学大学生创新性实验计划项目(1011)
关键词
弯起器
力学性能
试验研究
弯折半径
弯折角度
极限强度
预应力损失
the transfer apparatus for prestressed reinforcements performance
ultimate tensile strength
crooked process radius
marking forming angle
stretching control stress
