Flexural Behaviors of Damaged Full-Scale Highway Bridge Girder Strengthened by External Post Tension | Science Publications

American Journal of Engineering and Applied Sciences

Jaruek Teerawong¹  Sayan Sirimontree¹ 

关键词: Moment-curvature;    degradation;    effective flexural rigidity;    flexural stiffness;    pre-tension;    post-tension;    external post-tension;   

DOI  :  10.3844/ajeassp.2010.650.662

学科分类：工程和技术（综合）

来源: Science Publications

【 摘 要 】

Problem statement: Prestressed Concrete (PC) I section girder with ReinforcedConcrete (RC) topping slab has been widely applied to long span bridge girders for several years.A bridge girder is subjected to severe conditions caused by an aggressive environment andoverloading. A crack can be initiated and propagate when the tensile stress exceeds the tensilestrength of concrete due to overloading. Deterioration of the girder may be caused by a wide crackdue to corrosion of the reinforcement and other mechanisms. Prestressing force and flexuralstiffness (EI) of PC-I section girder are reduced depending on the level of overloading and thecorresponding damage. Approach: Full scale tests of Type III AASHTO highway girder with a 20cm thick RC topping slab were performed to study both the degradation process due tooverloading and also the effects of external post-tension in the recovery of structural performanceof a damaged highway PC bridge girder. Results: The results showed that degradation, loss ofinternal prestressing force in the PC-I girder and flexural stiffness of the composite girder dependdirectly on Damage Index (DI) expressed in terms of permanent deformation. External posttension with three levels of prestressing forces was applied to strengthen the damaged girder torecover its structural performance, flexural stiffness and strength. A simplified analytical model,verified by test results, was developed to predict flexural behaviors, loss of internal prestressingforce and flexural stiffness of highway girder due to overloading and also structural performanceof the strengthened girder. Conclusion: It was found that the required external prestressing forceto effectively recover structural performance of a damaged girder depended directly on thedamage index of the girder.

【 授权许可】

Unknown