冷拉热轧钢筋和热处理钢筋应力松弛损失研究

Study on Stress Relaxation Loss of Cold Rolled Steel and Treated Steel Bar

预应力松弛损失是预应力长期损失的重要组成部分,对预应力混凝土构件长期受力性能有很大影响,若长期损失预测得不准确,会引发桥梁运营后工作状况的劣化,如混凝土的开裂和过大的下挠或上拱。通过理论分析,综合了大量试验数据,基于对冷拉热轧钢筋和热处理钢筋应力松弛特性的研究分析,提出了考虑应力松弛损失时间和初始张拉控制应力影响的一般计算公式,弥补了现行规范的不足之处,为工程设计应用提供依据。

Stress relaxation is an important part of prestress loss of prestressed tendons, it has a great influence on the long-term performance of prestressed concrete members. Inaccurate prediction of long-term prestress losses can cause ser- viceability problems, including concrete crack and excessive deflection or camber. Through theoretical analysis and compre- hensive test data, based on study on stress relaxation loss of cold rolled steel and treated steel bar, a new model is provided considering the time-variation of prestressed relaxation loss and the initial tension control stress, which makes up for the de- ficiencies in the existing specification, and provides reference for the engineering design.