Computer-aided strengthening of masonry walls using fibre-reinforced polymer strips

Studies on the use of fibre-reinforced polymers (FRP) as strengthening materials of masonry walls have been numerous. FRP materials, particularly in the form of unidirectional strips, provide a highly effective method of structural intervention in masonry walls. However, the selection of the reinforcing pattern (positioning of the strips) and the calculation of respective cross sectional FRP areas still remains a problem, which is solved in this study through the development of a methodology that relies on strut-and-tie modelling. This methodology has been implemented in a computer programme that enables the definition of the locations where FRP strips should be placed in masonry walls subjected to in-plane loading. Moreover, the tensile forces in the ties can be used to calculate the required FRP cross section areas, hence the number of strips in each location. Hence, a valuable tool for the dimensioning of interventions in masonry walls using FRP materials in the form of strips has been developed. Applications of the tool in simple case studies (masonry walls with openings subjected to both vertical and horizontal loads) are also provided. Finally, a comparison between results predicted by this strut-and-tie model and those from an experimental study found in the literature adds some confidence to the model.