Free Shrinkage Strains of Box Girders with Concrete Overlays

The aging of reinforced concrete structures is one the biggest concerns in civil engineering today since billions dollars are spent annually on deck repairs and replacements. This study focuses rehabilitation box girders used bridge construction. Bridge with a new overlay possesses many challenges that involve cracking debonding caused by restraining effect substrate. leads to development tension stresses overlay, compression substrate, shear at interface. In order mitigate this type ensure desirable monolithic structural behavior rehabilitated bridge, long-term assessment free shrinkage strains acting necessary. conducts two-dimension finite element analysis girder evaluate humidity strain profiles different times. gradient between substrate generates differential volume changes overlay. deformations negligible, while subjected high shrinkage; 78% ultimate reached after 3 years, indicating susceptibility cracking.