PSI - Issue 44

Giuseppe Bramato et al. / Procedia Structural Integrity 44 (2023) 2302–2309 Author name / Structural Integrity Procedia 00 (2022) 000–000

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application area during the test. The Gauge Length ( GL ) was fixed equal to 100 mm per each specimen on which an extensometer was fixed to record the strain. Two series of specimens, each including nine coupons, were realized for a total of 18 specimens.

Fig. 1. FRCM specimens geometry The label utilized and reported in Table 1 is FRCM_X_Y_Z , where X represent the kind of fibre ( B =Basalt), Y the type of mortar (i.e. R for lime-based mortar and M for cementitious one) and Z the progressive number of the samples in the test sequence (i.e. from 1 to 9). 2.1.2 Shear-bond samples Four series of 3 specimens each were manufactured by varying the type of substrates and mortar. The cured time was fixed at 28 days in the same environmental conditions of FRCMs: 23 ± 2 °C and ~50 ± 5 % RH. In figure 2 the geometry of the bond specimens is drawn. Single masonry unit with dimensions of 380 (l) x 250 (w) x 110 (t) mm, were immersed in water until saturation and then the excess of water was naturally drained in standard condition for one hour (as suggested by manufacturer). Thereafter, the reinforcement was bonded to the substrate per a length of 320 (l b ) and a width of 100 (w b ) mm on the large side of the block, (Figure 2). Dry fabric was left unbonded from the substrates per a length of 400 (FL) mm. Even in this case, after curing time, steel tabs were epoxy glued to make the gripping action more effective.

Fig. 2. Shear bond specimens’ geometry

Nomenclature W_X_Y_Z was used; where W indicates the type of substrate ( C =Calcarenite, PL=Pietra Leccese), X the dry fibre type ( B =Basalt), Y the reinforcement mortar used ( R =lime-based and M =cementitious) and Z the progressive number of the samples in the test sequence (i.e. from 1 to 4). 2.1.3 Test set-up The same universal testing machine was used for both type of test by changing tool. The single face shear test was performed by designing a specific test set-up as shown in Figure 3a and 3b and in depth detailed in Bramato et al. (2022).

a) c) Figure 3: Test set-up (Bramato et al 2022): a) universal testing machine; b) direct single-lap shear bond test; c) tensile test on FRCMs b)