中文摘要：

为了得到重载交通对预应力混凝土梁的疲劳性能影响,对9根预应力混凝土模型梁分别进行静载试验和等幅疲劳试验研究。研究结果表明,部分试验梁在经历过200万次疲劳荷载作用后,其静力极限强度不但没有大幅度降低,反而略有提高;在重载作用下的疲劳破坏均始于非预应力钢筋的疲劳断裂;试验过程中疲劳损伤明显呈三阶段发展规律,当疲劳荷载上限达到0.7倍的极限荷载时,疲劳寿命大于200万次,当疲劳荷载上限达到0.75倍极限荷载时,疲劳寿命仅为10.2万次,当疲劳荷载上限达到0.85倍的极限荷载时,预应力混凝土梁的疲劳寿命仅为5.1万次;得到了预应力混凝土梁的容许疲劳寿命方程。

英文摘要：

In order to get the impact of heavy load traffic on fatigue performance of pre-stressed concrete beams,static load tests and constant amplitude fatigue experiments were conducted on 9 pre-stressed concrete beam models respectively. The results show that static ultimate strength of part of the experimental beams not only fails to reduce significantly but slightly increases after experiencing 2 million times of fatigue load actions. The fatigue damage under heavy load starts from fatigue fracture of non-pre-stressed reinforcement. The fatigue damage during the test shows three-stage development rule clearly.When the upper limit of fatigue load reaches the 0. 7 times of the ultimate load,the fatigue life is over 2 million times.When the upper limit of fatigue load reaches the 0. 75 times of the ultimate load,the fatigue life is only 102 000 times.When the upper limit of fatigue load reaches the 0. 85 times of the ultimate load,the fatigue life is only 51 000 times. Then the allowed fatigue life equation of pre-stressed concrete beam was obtained.