Structural analysis of a concrete elements strengthened with FRP using different Codes and Manuals

The paper consists of general information’s of FRP laminate and the advances in this field. As a new material is not completely under the strict rules of existing Codes, but the applications is on the very high development. Therefore the existing manuals are only based in empirical expressions which diverge in different manuals. As a new material, FRP is oriented in specific fields, especially in retrofitting existing structures but also in new contemporary buildings. The main purpose of this paper is to promote the different benefits of this material which highly consist on their physical attributions. Since it is a new field of research, a comparison of different Codes or Manuals was much needed to see the behaviour of reinforced concrete elements reinforced or strengthened with FRP. The paper treats a Design example of a reinforced concrete element retrofitted with FRP laminates. Two different design Codes or Manuals are used for this example and the results are used for compare the parameters and behaviour under same loading conditions. The output data is analysed to come to a conclusion, which will demonstrate the behaviour of the retrofitted RC elements with FRP laminate. In first stage the paper consist on the main principles and parameters of the loadings and materials. Calculation formulas will be analysed and differentiated from the manuals. Methods of FRP application in the element and also the variety of structural improvements it can make in concrete elements are also part of this analyse. Secondly, an example of a reinforced concrete element retrofitted with FRP is used to demonstrate the differences between the applications of two different manuals. An algorithm will reveal the design approach of the two manuals, which than will be used to develop the case. The concrete element will be analysed firstly without FRP application at which loads will be applied to show the internal influences of these impacts. The same concrete element will be empirically tested only this time with the FRP laminate retrofitting. The same approach will be used for the two different manuals, which will give different output results. Lastly, the results are used to show the indication of FRP in improving especially the flexural strength in concrete elements and overall. The paper will be also followed by a presentation of the design methods using Microsoft Office Program (Excel), used for this example, which will ease the work of designing FRP retrofitting. In addition to that we will also compare the advantages and disadvantages of the used design manuals and codes.