预应力加固混凝土框架梁体外筋应力增量试验研究

Stress increment analysis on external steel bar of external prestressing reinforce concrete frame beam

体外筋应力增量是体外预应力混凝土梁强度设计中的一个重要指标。通过对一组单跨框架梁的静载试验,总结了体外筋应力增量随荷载增长变化及其与梁跨中挠度近似成直线关系的规律;论证了由于框架柱对框架梁存在侧向约束的作用,降低了体外筋的有效预应力和应力增量,为体外预应力加固混凝土框架梁的设计提供了一些参考依据。

The stress increment is an important index for the strength design of externally prestressed beam. According to a static test of a set of span frame beams,the rules that the external steel bar stress increment changes by loading and that it is almost linear relation with middle deflection of the beam are summarized; According to the contrast between theoretical arithmetic and experimental data, because of lateral restraint exist in frame beam, the stress increment and effective prestress of the external steel bar are reduced. Provide some reference for the design of external steel bar of external prestressing reinforce concrete frame beam.