Issue 51

G. Ramaglia et alii, Frattura ed Integrità Strutturale, 51 (2020) 288-312; DOI: 10.3221/IGF-ESIS.51.23 303 known. The weak influence of the tensile strength of masonry on the axial capacity of the strengthened masonry element is clear, by the experimental results also. It is due to the prevailing confinement effect if compared to that of tensile strength of masonry. The Drucker-Prager model strongly overestimates the experimental results. This effect is very clear for high values of the confining stress, while, for low confining stresses, the mechanical model provides reliable results. However, a great number of tests were carried out at high confining stress values. Therefore, on the entire experimental sample the model provides a weak estimation of the axial capacity of masonry columns wrapped with composites. Furthermore, it results strongly influenced by the tensile strength of masonry providing confinement curves strongly different to change the tensile strength of masonry. The Henchy-Von Mises model does not depend on the normalized tensile strength of confined material. The theoretical and experimental comparison showed a strong underestimation of the experimental values. This effect is clear for the entire confining stress field. The Mohr-Coulomb provides a clear overestimation of the experimental results for the entire experimental sample. In fact, also for low values of the effective confining stress the experimental results are not well fitted by the theoretical results. Furthermore, Mohr-Coulomb results are strongly influenced by the tensile strength of masonry. Finally, the reliability of the Stassi-D’Alia model was remarked by the best values of three statistical parameters: mean absolute percentage error (MAPE), mean square error (MSE) and coefficient of determination (R 2 ). R EFERENCES [1] Ramaglia, G., Fabbrocino, F., Lignola, G.P., Prota, A. (2019). 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