The selection of the most proper strengthening method/system with an assessment of its effectiveness is quite complicated in the case of masonry structures, mainly due to their huge diversity in materials. The most popular strengthening materials based on the composite fibres and are laid on the masonry wall using epoxy adhesives (FRP system) or mineral mortars (FRCM system). This article presents a comparison of external strengthening made using different glass-fibre-based materials on the behaviour of specific masonry walls. The walls are made of AAC blocks (Autoclaved Aerated Concrete), commonly used in rather low urban buildings or skeleton construction. As a strengthening material the GFRP sheets and two types of glass meshes are used. The walls are subjected to diagonal compression, which reflects the shearing of the walls. The scope of research describes cracking stage, shear capacity and analysis of the mode of failure of tested walls.

The composite materials as FRP (Fiber Reinforced Polymers), which are characterized by benefits resulting from the combination of high strength reinforcement (as carbon, glass, steel or aramid fibers) with synthetic matrix are increasingly used to reinforce existing structures. Reinforcing System as FRCM (Fibre Reinforced Cementitious Matrix), which includes, among others, Ruredil X Mesh Gold System, is much less commonly used. However, the uniform and practical methods for calculating composite reinforced structures are not determined. Especially when considering the real conditions of structure exploitation, which requires further research in this field. In the paper the initial loading level influence on the efficiency of reinforced concrete beams strengthen using system Ruredil X Mesh Gold was investigated.