Analysis of Reinforced Concrete Beams Strengthened with Composites Subjected to Fatigue Loading

Synopsis: Use of high strength composites for repair and rehabilitation of bridges and parking decks is steadily increasing. Since these structures are subjected to fatigue loading, the performance of strengthened beams under this type of loading needs to be evaluated. An analytical procedure that incorporates cyclic creep of concrete and degradation of flexural stiffness is presented. The method is verified by computing cycle dependent deflections and comparing them with experimental results. The results presented in this paper also provide a summary of an experimental investigation, in which reinforced concrete beams were strengthened with glass fabrics (sheets) and subjected to fatigue loading. The comparison shows that the analytical model provides reasonably accurate prediction of deflections, for both reinforced beams and reinforced concrete beams reinforced with composites. Although Glass fiber composites were used for the evaluation, the model is also applicable to other types of fibers.