5In the last decades, there are many reports on the use of composites as reinforcement of structural 6 elements under compression, especially regarding the confinement of concrete structures, but works 7 on stone or masonry columns are limited. Initially, FRP jackets were used because their high 8 structural performance. However, they present some drawbacks like aesthetics or water 9 impermeability, which can affect their applicability in historical constructions made in stone. 10Recently, FRCM appeared as an alternative with better compatibility with masonry structures. In 11 the present study, a comparison between different composite materials to confine masonry 12 specimens was made. FRPs with carbon or glass fibers and epoxy matrix, and FRCM with basalt or 13 glass fiber mesh in a cementitious matrix were used to confine masonry, made in calcarenite 14 cylindrical pieces and lime mortar. Strength and ductility gains under compressive loads were 15 measured, and compared to the recommendations of different guidelines. Unidirectional FRPs were 16 the optimal solution from a strengthening point of view. On the other hand, FRCM confinement 17 offered more ductility than unreinforced masonry, but showed a softening behavior. Finally, 18 regarding the studied design codes, the specific parameters included for masonry structures seemed 19 enough to obtain accurate predictions of the compressive strength increase due to the confinement 20 with the tested composites. 21Keywords: masonry, stone, confinement, FRP, FRCM, TRM. 22 carbon or glass fiber fabrics (CFRP or GFRP respectively), which were casted as continuous jackets 54 or narrower horizontal stripes with different widths and separations. Continuous FRP jackets 55 increased 93% the strength of the bare masonry, with 200% increase of the ultimate strain. On the 56 other hand, non-continuous confinements may produce the failure of the unreinforced part of the 57 specimen, but if the separation between FRP stripes was limited the performance was similar than a 58 (Figure 2(e)), and a cement based mortar matrix. 132
Masonry walls exhibit low tensile strength and high material heterogeneity, which makes them especially vulnerable against cyclic loading conditions, such as those typical in earthquakes. This paper presents the experimental results obtained from tests on three masonry walls reinforced with textile reinforced mortar (TRM) materials subjected to in-plane cyclic loading. These full-scale masonry walls were tested in the LARGE laboratory at the University of Alicante (Alicante, Spain). The walls had been built using a traditional construction technique, with solid clay bricks layered with lime mortar. One specimen was tested and damaged by in-plane cyclic loading and was subsequently strengthened by a vertical layer of TRM with an overlapping of 200 mm. It was then tested again until failure in a second test. In addition, another undamaged specimen had been previously reinforced with the same TRM technique and tested until failure, thus providing a third test. A network of sensors and digital image correlation systems were used to monitor displacements and crack patterns. The comparison between these experimental results made it possible to assess the effectiveness of TRM in restoring the structural integrity of damaged masonry walls and almost doubling their load-bearing capacity under cyclic loads. Conclusions obtained here provide valuable information to the scientific community, architects and structural engineers about the strengthening and repair of severely damaged masonry walls.
The mechanical properties of stone materials can be severely affected by exposure to high temperatures. The effect of fire on stone buildings could cause irreversible damage and make it necessary to retrofit the affected elements. Particularly, the strengthening of columns by confinement with composites has been widely improved during the last decades. Today, fiber reinforced polymer (FRP) confinement represents a very interesting alternative to traditional steel solutions. This work studied the behavior of cylindrical stone specimens subjected to real fire action and confined by means of CFRP or GFRP jackets, with the aim of assessing the effectiveness of these reinforcement systems applied to a material that has previously been seriously damaged by high temperature exposure. In general, the strengthened samples showed notable increases in strength and ductility. The response seemed to depend basically on the FRP properties and not on the degree of damage that the stone core may have suffered. Finally, the results obtained experimentally were compared with the confinement models proposed by the available design guides, in order to evaluate the accuracy that these models can offer under the different situations addressed in this research.
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