Strengthening of Arched Masonry Structures by Additional Reinforcement: Design Approaches and Comparison to Experiments

The primary aim of this article is to present design approaches for calculating the additional strengthening of masonry arches with the use of the Strut-and-Tie model and applicable standards and their comparison to the experiments. Experiments have proven the functionality of the described method of strengthening by additional inserted non-prestressed reinforcement from the face of the vault. The presented method is one of the methods of maintaining historical vaulted masonry structures, and is also used to improve the behaviour of newly designed masonry structures. This method of strengthening has its advantages, especially in the minimization of alterations to the structure and its simplicity of application. To compare the results and verify the vaults behaviour, experiments were performed with using a metallic helical reinforcement and non-metallic composite glass reinforcement. These experiments have demonstrated the significant influence of additional reinforcement on the carrying capacity of masonry vaults. The growth of bearing capacity was more than eight-fold. From a comparison of design approaches to experiments is evident that approaches to the design of additionally strengthened masonry based on valid standards are possible. The comparison of results moreover demonstrates the possibility of using approaches based on the Strut-and-Tie model