Evaluation and Damage Repair of 23-Year Old Prestressed Bridge Box Girders

在拆除雷诺一座有23年历史的混凝土桥梁时，回收了大量长达69英尺的现浇预应力混凝土箱梁，状态良好。其中六根梁已捐赠给内华达大学雷诺分校(UNR)用于研究目的。这些梁为研究现有结构的行为、设计、修复和疲劳寿命的不同方面提供了一个极好的机会。能源部已提供研究经费，对两根梁进行测试，以确定其实际刚度和强度，并对梁的修复进行有限的研究。该建议的主要目的是研究另外四根梁，以确定(1)实际预应力，(2)在除冰盐中暴露23年后氯离子污染的程度，(3)低水平损伤对剩余寿命的影响，以及(4)碰撞损坏梁的适当修复技术，并调查修复梁的疲劳性能。

During the demolition of a 23-year old concrete bridge in Reno, a large number of plant-cast prestressed concrete box girders with a length of 69' were recovered in good condition. Six of the girders have been donated to the University of Nevada, Reno (UNR), for research purpose. These girders provide an excellent opportunity to study different aspects of the behavior, design, repair, and fatigue life of existing structures. Research funds have been received from the Department of Energy to test two girders to determine their actual stiffness and strength and to conduct limited studies on the repair of the girders. The primary objective of this proposal is to study four additional girders to determine (1) the actual prestress forces, (2) the extent of chloride contamination after 23 years of exposure to deicing salt, (3) the effect of low-level damage on the remaining life, and (4) appropriate repair techniques for girders damaged by collision, and to investigate the fatigue performance of the repaired girders.