Shrinkage Effect on Beams Strengthened with Additional Concrete Layers

A common technique used to increase the flexural capacity of reinforced concrete beams is theaddition of concrete layers in the compressive or in the tensile side. Until now, there are limitedstudies for the effect of the concrete shrinkage on the performance of the strengthened beams. Inmost of the published studies, concrete shrinkage is ignored and perfect connection is assumedbetween the old and the new concrete which is not conservative. In this study full scale beamsstrengthened with additional concrete layers in the tensile side have been investigated. The resultsof an experimental investigation together with numerical and analytical results are presented. Thecrucial effect of the concrete shrinkage on the slip of the interface is highlighted and the interactionbetween the slip induced by concrete shrinkage and the slip due to bending loading is presented.