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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Fig. 4 For specimens with (a) single S.A. and (b) double S.A. and two anchor lengths (la), the fiber axial stress vs global slip curves are presented.

For every load level in the bonded area, the fiber axial strain profile was replicated using the SGs. Additionally, one SG was glued into the unbonded textile's core strand. The strain profiles of specimens strengthened with pre-impregnated fiber in both single and double spike anchor configurations are shown in Fig. 5. It is possible to observe that the strain profile of the specimen with a single spike anchor is similar to that of the configuration without S.A. by comparing the fiber axial strain profiles in Fig. 5a and Fig. 5b. This outcome most likely depends on the distance, or roughly the effective bonded length l b,eff , between the origin of the curvilinear abscissa y and the spike anchor y SA . For FRCM systems, the effective bonded length is the minimum length required to develop the masonry-matrix interface's load-carrying capacity. In the double spike anchor configuration, the corresponding strain profile demonstrates the first spike anchor's fiber restraint effect, with a distance of about 60 mm. In fact, the strain profile is constant from y=0 to y SA and equal to 0 for y> y SA .

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