曾庆响^1,2，韩大建¹
(1 华南理工大学亚热带建筑科学国家重点实验室，广州510640; 2五邑大学土木建筑学院，江门529020)

[摘要] 预应力混凝土梁桥因具有良好的受力性能而在桥梁工程中得到广泛应用。混凝土桥梁的开裂和挠度过大已经逐步成为普遍现象，桥梁结构的加固改造已经成为学术研究和工程应用的热点。介绍了桥梁加固设计的基本原则。将桥梁结构的加固方法划分为主动加固法和被动加固法两大类。分析了截面增大加固法、粘贴钢板和纤维复合材料加固法、体外预应力加固法和改变结构体系加固法等的特点与适用范围。总结了桥梁工程中裂缝处理的常用方法和常用加固材料的力学性能。指出了桥梁工程加崮中应注意的主要问题。
[关键词] 混凝土桥梁；加固；体外预应力；裂缝；纤维复合材料

Strengthening and crack treatments for prestressed concrete girder bridges
Zeng Qingxiang^1,2, Han Dajian¹
(1 State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510640, China; 2 School of Civil Engineering & Architecture, Wuyi University, Jiangmen 529020, China)

Abstract: Prestressed concrete box girder  (PC bridges)  is widely applied in bridge engineering for its favorable mechanical performance. Cracking and over-deformation have been beconung the common phenomenon for PC bridges. The problem of structural strengthening for concrete girder bridges is universally concerned in the field of academic research and engineering application in bridge structure engineering. The structural strengthening methods in PC girder are classified into two categories, active strengthening method and passive strengthening method. The features and application scope of some structural strengthening methods, such as structure member strengthening with RC & PC, structure member strengthening with bonded steel plate or fiber reinforced polymer, structure member strengthening with external prestressing, strengthening by changing structure system and so on, are analyzed for PC bridges. Finally, some treatment method of cracks and mechanical properties index of strengthening materials for PC bridges are summarized briefly. Some main problems should be paid attention in structure strengthening are pointed out for the benefit of further strengthening design for PC bridges.
Keywords: prestressed concrete bridge; strengthening; external prestressing; crack; fiber reinforced polymer( FRP)