Problems of Masonry Strengthening with Carbon- and Glass Fibre Fabric

The failure mechanism of masonry columns is characterized by tensile crack appearance due to the effect of transversal tensile stresses, which results in load bearing capacity lower than the ultimate load bearing capacity of masonry. Experimental research of the strengthening of masonry columns with carbon-or glass-fibre fabric showed a prominent effect of FRP on the reduction of characteristic tensile cracks and thus on a significant increase in the load bearing capacity. Experimental research also involves the monitoring of the effect of some secondary factors that may affect the behaviour of strengthened masonry under load and its ultimate strength. They include, among others, perfect adhesion between the masonry and the strengthening fabric, the installation procedure, the volume and practical application of the strengthening fabric on the masonry, the effect of masonry moisture content and the workmanship of anchorage points of the strengthening fabric. The paper presents partial results of the investigation of the effect of these secondary factors on the load-bearing capacity and the type of failure of strengthened masonry.