PSI - Issue 64

Rebecca Grazzini et al. / Procedia Structural Integrity 64 (2024) 1532–1539 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

1538

7

For the coated textiles, the maximum peak shear seems to have been provided by lime and gypsum, with comparable values in shear and slip. However, cement matrix could offer the greatest slip capacity at peak, i.e. +49% and +67% compared to gypsum and lime matrices, respectively.

Table 3. Results of CML back calibration

P1 [N] 1 ሾ ሿ 1 ሾ ƒሿ 488 0.07 0.154

P2 [N] 1 ሾ ሿ 1 ሾ ƒሿ 780 0.12 0.265

P3 [N]

0 ሾ ƒሿ [mm] ሾ ƒሿ 0.208 0.382 0.011

Group

Sst -L-D Sst -L-C Sst -G-D Sst -G-C Sst -C-D Sst -C-C

1225

1550

0.25 0.25 0.32 0.05 0.63

0.432 0.083 0.435 0.112 0.410

2500

0.56 0.32 0.63 0.11 0.94

0.973 0.106 0.857 0.255 0.607

-

-

-

-

647

825

915

0.347

0.39

0.088

1750

2500

-

-

-

-

348

702

1120

0.191

0.313

0.062

2394

2987

-

-

-

-

Fig. 4. Estimation of the global load slip diagram (orange curve) for (a) Sst-L-D; (b) Sst-G-D; (c) Sst-C-D; (d) Sst-L-C; (e) Sst-G-C; (f) Sst-C-C

4. Conclusions An experimental and analytical investigation is carried out on six different FRCM systems, composed of the same glass-fiber textile, dry or epoxy-coated, and three different matrices based on cement, lime, and gypsum binders. In particular, the single shear test has been performed and the experimental results have been used to implement an indirect calibration of the CMLs. The assumptions considered are that the internal and external interfaces experience two different shear stress-slip laws and that the brick and both the matrix layers are rigid. The main conclusions are: from the experimental results it is possible to observe that the coating improves the maximum load capacity remarkably. On the other hand, a brittle failure mode occurs because of the textile rupture; taking into account the different global behavior, two CMLs are considered for dry and coated samples, a trilinear and bi-linear respectively; as regards the dry samples CML, the lime mortar shows the highest peak shear stress while the gypsum the lowest one. For the friction values the gypsum reaches the highest value; as regards the coated samples CML, the cement shows the lowest peak stress but the greatest slip capacity.