Interfacial Shear Behaviour for Reinforced Concrete Girder Strengthened with Post-Tensioned Concrete Jacket
Volume Title: ICASGE2025
Paper ID : 1168-ICASGE
Authors
1Ain Shams University
2Reinforced Concrete Structures (RCS)
Abstract
Strengthening and retrofitting of existing reinforced concrete structures are mostly needed cause of deterioration of structures, overloading and construction problems. Different types of strengthening are concrete jacket, steel jacket and Fiber Reinforced Polymers (FRP), however these strengthening types improve the ultimate load capacity and ductility. In addition to improve the ultimate load, strengthening using external prestressing system could improve the serviceability limit state (deflection and crack width) due to the added axial load and the upper deflection (camber). During the last few decades, external prestressing has become a popular choice for strengthening of bridges and building structures, but the main problem of this type of strengthening is exposed to vandalism, fire and corrosion, and it provides little warnings at ultimate limit states. So, strengthening using post-tensioned concrete jacket is considered an effective technique for retrofitting and strengthening of structures to increase ultimate load capacity and serviceability limit state. In this study, different spacing of shear dowels between post-tensioned concrete jacket and existing girder were tested and the results were observed with clear comparison. An experimental program is consisting of three simply supported T-section strengthened with post-tensioned concrete jackets. Each girder was loaded at its mid-span with two concentrated loads spaced by 1.20m. The program including specimens with different spacing and diameter of shear dowels connecting between post-tensioned concrete jacket and existing girder. Contribution of the different shear dowels arrangement to the overall deformational behaviour of the girders including slip values, strain of shear dowels and girder ductility are also introduced.
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