In the construction industry, the use of natural fabrics as a reinforcement for cement-based composites has shown great potential. The use of these sustainable composites to provide strengthening or repair old masonry structures that exhibit structural problems mainly due to a poor tensile strength of the mortar/brick joints is revealed to be a promising area of research. One of the most significant load conditions affecting the mechanical response of masonry structures occurs when axial bending loads are applied on the resistant cross-section. In this study, three different types of masonry elements were built using clay bricks and a lime-based mortar. After 28 days, the samples were subjected to concentric and eccentric compressive loads. In order to produce significant bending effects, the compressive loads were applied with large eccentricity, and a sudden failure characterized the behavior of the unreinforced masonry (URM) elements. The tested masonry specimens were repaired using fabric-reinforced cementitious matrix (FRCM) composites produced using bi-directional flax and polyparaphenylene benzobisoxazole (PBO) fabrics. The mechanical behavior of the URM and repaired samples was compared in terms of load-displacement and moment-curvature responses. Furthermore, the results achieved using flax-FRCM composites were compared with those of using PBO-FRCM composites.
28 October 2018 in Construction and Building Materials
Masonry structures with fictile tubules were a distinctive building technique of the Mediterranean area. This technique dates back to Roman and early Christian times, used to build vaulted constructions and domes with various geometrical forms by virtue of their modular structure. In the present work, experimental tests were carried out to identify the mechanical properties of hollow clay fictile tubules and a possible reinforcing technique for existing buildings employing such elements. The experimental results were then validated by devising and analyzing numerical models with the FE software Abaqus, also aimed at investigating the structural behavior of an arch via linear and nonlinear static analyses.
23 September 2013 in Conference Papers in Materials Science
This paper deals with the experimental characterization of the tensile behavior of fiber-based composites and flexural strength of natural fiber-reinforced polymer (NFRP) sheets externally glued on masonry bricks, in terms of load capacity and stress distribution along the bonded length. The bricks adopted for this experimentation are solid clay bricks, typically used in ancient masonry structures. Nonimpregnated and impregnated flax, hemp, jute, and sisal fibers were examined. Two types of matrices have been used, polymer matrices and mortar-based matrices. Composite materials defined as NFRP (Natural Fiber Reinforced Polymer) and NFRG (Natural Fiber Reinforced Grout) were obtained.