PSI - Issue 44

Francesca Ferretti et al. / Procedia Structural Integrity 44 (2023) 2254–2261 Ferretti et al./ Structural Integrity Procedia 00 (2022) 000–000

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systems does not appear to create considerable variations in shear stiffness since the shear modulus ( G ) is almost similar among the tested samples. The mortar matrix fractured more in the post-peak phase, and the role of the fibers became more essential, affecting the failure mode and deformation capacity of strengthened samples. The highest pseudo-ductility values, i.e., more than double the value of the unreinforced panel, were obtained for samples CD_3 and CD_4 (Table 4), confirming a more ductile behavior of the strengthened samples. 4. Conclusions In the present paper, the efficiency of different strengthening techniques, involving the application of structural repointing combined with FRCM and CRM, was studied by subjecting URM and strengthened masonry panels to diagonal compression tests. Results showed that the strengthening systems were able to improve the structural behavior of the masonry panels, both in terms of bearing capacity and ultimate deformations. This confirms the suitability of the considered strengthening schemes in improving shear behavior of masonry panels without determining strong stiffness variations in existing buildings. The efficiency of the solutions involving the structural repointing technique represents an important result, considering that this technique is the sole applicable when the masonry texture must remain visible for conservative reasons, such as in historical constructions. Acknowledgements The technical staff of the Interdepartmental Centre for Industrial Research (CIRI Buildings & Construction) is gratefully acknowledged for the work during the setup of the tests. References Calderini, C., Cattari, S., & Lagomarsino, S. (2009). In-plane strength of unreinforced masonry piers. Earthquake Engineering and Structural Dynamics, 38(2), 243–67. https://doi.org/10.1002/eqe.860. Calderini, C., Cattari, S., & Lagomarsino, S. (2010). The use of the diagonal compression test to identify the shear mechanical parameters of masonry. Construction and Building Materials, 24(5), 677–685. https://doi.org/10.1016/j.conbuildmat.2009.11.001 Casacci, S., Gentilini, C., Di Tommaso, A., & Oliveira, D. V. (2019). Shear strengthening of masonry wallettes resorting to structural repointing and FRCM composites. Construction and Building Materials, 206, 19–34. https://doi.org/10.1016/j.conbuildmat.2019.02.044 D’Antino, T., Calabrese, A. S., & Poggi, C. (2020). Experimental procedures for the mechanical characterization of composite reinforced mortar (CRM) systems for retrofitting of masonry structures. Materials and Structures, 53(4), 94. https://doi.org/10.1617/s11527-020-01529-1 D’Antino, T., Carozzi, F. G., & Poggi, C. (2019). Diagonal shear behavior of historic walls strengthened with composite reinforced mortar (CRM). Materials and Structures, 52(6), 114. https://doi.org/10.1617/s11527-019-1414-1 Del Zoppo, M., Di Ludovico, M., & Prota, A. (2019). Analysis of FRCM and CRM parameters for the in-plane shear strengthening of different URM types. Composites Part B Engineering, 171, 20–33. https://doi.org/10.1016/j.compositesb.2019.04.020. Ferretti, F., Incerti, A., Tilocca, A.R., & Mazzotti, C. (2021). In-plane shear behavior of stone masonry panels strengthened through grout injection and Fiber Reinforced Cementitious Matrices. International Journal of Architectural Heritage, 15(10), 1375-1394. https://doi.org/10.1080/15583058.2019.1675803 Ferretti, F., & Mazzotti, C. (2021). FRCM/SRG strengthened masonry in diagonal compression: Experimental results and analytical approach proposal. Construction and Building Materials, 283, 122766. https://doi.org/10.1016/j.conbuildmat.2021.122766 Gattesco, N., & Boem, I. (2015). Experimental and analytical study to evaluate the effectiveness of an in-plane reinforcement for masonry walls using GFRP meshes. Construction and Building Materials, 88, 94–104. https://doi.org/10.1016/j.conbuildmat.2015.04.014 Incerti, A., Ferretti, F., & Mazzotti, C. (2019). FRCM strengthening systems efficiency on the shear behavior of pre-damaged masonry panels: an experimental study. Journal of Building Pathology and Rehabilitation, 4(1), 14. https://doi.org/10.1007/s41024-019-0053-9 Marcari, G., Basili, M., & Vestroni, F. (2017). Experimental investigation of tuff masonry panels reinforced with surface bonded basalt textile reinforced mortar. Composites Part B: Engineering, 108, 131–142. https://doi.org/10.1016/j.compositesb.2016.09.094 Yardim, Y., & Lalaj, O. (2016). Shear strengthening of unreinforced masonry wall with different fiber reinforced mortar jacketing. Construction and Building Materials, 102, 149–154. https://doi.org/10.1016/j.conbuildmat.2015.10.095