PSI - Issue 62

Paolo Zampieri et al. / Procedia Structural Integrity 62 (2024) 446–453 Paolo Zampieri/ Structural Integrity Procedia 00 (2019) 000 – 000

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Debonding between the fibre and matrix is the primary failure mode of the specimens without S.A., as seen throughout the test and from the analysis of the σ yy – S g curves presented in Fig. 6a. Therefore, there is only friction between the inner fibre region (unbonded) and the external fibre layer (bonded to the matrix) in the final phase (constant) of the σ yy – S g curves, which also have an initial linear phase, a nonlinear phase up to the maximum, and a nonlinear softening. When compared to specimens without S.A., the results of tests conducted on specimens with dry fibre and S.A. show a significant difference in performance (Fig. 6b). The σ yy – S g relationship is similar to specimens without S.A. when the fibre tensioned length, or the length over which the fibre immersed in the matrix is subjected to non-zero axial stress and strain, is less than y SA . The disassociation of the central bundle from the other longitudinal bundles is caused by the local effects produced by the spike anchor. This suggests local damage along the textile-external mortar layer interface and the failure of the textile-mortar mechanical interlocking mechanism at the first peak in the curves illustrated in Fig. 6b. Since the fiber's central bundle is more tensioned than the others, load increases are therefore permitted up until its tensile rupture. Furthermore, it is possible to deduce from the strain profiles in Fig. 7 that the presence of S.A. has no effect on the strain profile until the slip between the fibre and the matrix involves the spike anchor.

Fig. 7 Strain distribution for different values of dry fiber normal stress: (a) R1_350_SG_7_D; and (b) R1_350_Pc1-Lc1_SG_13_D.

4. Conclusion This research presents the results of an experimental campaign that examines the stress-transfer mechanisms of FRCM strengthened curvilinear masonry prisms in the presence of S.A. and both carbon dry and impregnated fiber. A limitation of this study is that the experiments were calibrated using radii of curvature R in relation to specimens of masonry arches that underwent destructive testing; these specimens will be the focus of future publications. This is the reason why a wider range of curvature radii was not examined. The radii employed are, nevertheless, less than those of actual stone arch bridges. Another limitation is that a large degree of variability was observed in the experiments as a result of extra uncertainties arising from the creation of the curved specimens. However, we have succeeded in our investigation of the process of load transmission between the brick substrate and the composite for both of the considered radii in addition to the existence of the S.A.. When it comes to the advantages and disadvantages of using one type of fabric over another, the most important benefit of impregnated fiber is its