FLEXURAL STRENGTHENING OF REINFORCED CONCRETE SLABS BY ADDING A CONCRETE OVERLAY
André Pereira Pinto1; Ibrahim Abd El Malik Shehata1
1 Coppe - Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia da UFRJ
doi:10.20906/CPS/CILAMCE2017-0151
Resumo
Concrete structures require periodically maintenance, in order to preserve theirs structural and aesthetics properties. Once the behavior of concrete structures appear to be inadequate, due to degradation or by the change of the type of loading, the intervention becomes mandatory in order to rehabilitate them. Actually, there are different types of techniques available for structural strengthening, each technique has advantages and disadvantages, thus the selection of the proper technique that will be used depend on the technical and economic requirements for the specific case under study. One of the available techniques of repair and strengthening of the reinforced concrete slabs is by adding a concrete overlay over the compressed face. Within this context, this paper presents analytical methodology to calculate the resistance of strengthened slabs, taking into account the concrete compressive strength, the overlay thickness and the existing slab deformations before the intervention. To validate the method proposed tests were made using numerical models development in a software based on the Finite Elements Method taking into consideration the concrete cracking, the existing slab deformation due the dead loads and the used of shear connector crossing the interface concrete overlay-slab. The numerical results provided information about the behavior of the strengthened elements as the distribution of the shear stress in the shear connectors along the interface and the evolution of the normal stress in the overlay-slab section before and after strengthening. Finally, based on the results of these analyses, recommendations for the slab strengthening project using this technique will be made.
Palavras-chave: Slab; Reinforced Concrete; Strengthening