钢绞线和精轧螺纹钢筋的竖向预应力对比研究

文章对箱梁腹板竖向预应力钢绞线和精轧螺纹钢筋进行对比试验,研究钢绞线和精轧螺纹钢筋竖向预应力的规律,分析了两种不同竖向预应力体系的特征和预应力损失,结果表明钢绞线和精轧螺纹钢筋的第一次张拉预应力损失率和两者长期损失率基本相同,竖向预应力钢绞线的第二次张拉效果明显,预应力损失率较第一次张拉减小近1/2,对于控制主拉应力较大的高腹板的竖向预应力可靠度较大,证明了钢绞线作为竖向预应力筋的实际意义,为工程设计提供参考.

The Comparative Study of the Vertical Prestress of Steel Wires and Fine Rolling Twisted Steel

Through the contrastive test on the vertical prestressed steel wires and fine rolling twisted steel,the paper studies the principles of the two vertical prestressed steels and analyses the features and the pre-stress loss of these two systems.The results indicate that the loss rates of the first tension pre-stress of the two steels are basically the same and so do the long-term loss rates.However,the second tension effect of the vertical pre-stressed steel wires is more obvious and its loss rate is reduced about 1/2 compared to the first one.There is a higher degree of reliability on vertical pre-stress of web of the box-girder which has larger controlled tensile stress.It proves the practical significance of using the steel wires as the vertical pre-stressed wire and provides a reference for the engineering design.