PSI - Issue 64

Pier Francesco Greco et al. / Procedia Structural Integrity 64 (2024) 1888–1895 Pier Francesco Greco/ Structural Integrity Procedia 00 (2019) 000 – 000

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Table 1. Mechanical properties of tested specimens under three point bending test. Specimen  peak(MPa) ε peak ε max

E(MPa)

G f

rG f

0.026 0.034 0.028 0.013 0.024 0.028 0.033 0.028 0.014

0.026 0.034 0.028 0.052 0.119 0.078 0.120 0.119 0.060

1.08 2.29 1.60 1.42 4.88 3.46 6.50 4.18 2.48

0.00% 0.00% 0.00% 30.3% 63.1% 56.4% 63.5% 69.6% 73.0%

M1 M2 M3

0.97 1.68 1.59 1.03 1.50 1.32 1.85 1.30 1.05

73.04 84.30

103.25

MH1 MH2 MH3 MS1 MS2 MS3

78.56 83.46 71.40 88.63

100.15 110.77

4. UNIAXIAL COMPRESSION TEST The two stumps resulting from a single prism subjected to a three-point bending test were further subjected to the uniaxial compression test. The stumps were placed on a supportive base as depicted in Fig. 3-a-h. A universal testing machine applied compressive force to the specimens in a single direction. Each sample was loaded with a plate measuring 40x40 mm, at a controlled displacement rate of 0.5 mm/min, using a 30 kN load cell, as shown in Fig. 3. Cracks were observed forming step by step during loading, with varying behavior observed between unreinforced specimens and fiber-reinforced ones. Stress-strain curves were obtained from recorded force and displacement data, as shown in Fig. 4-a, b, c. Similar to three-point bending tests the fiber reinforced samples show a different softening behavior with higher rG f due to the binding effect of the fibers. The obtained mechanical properties are graphically compared in Fig. 4-d, e, f and reported in table 2, using the same nomenclature already discussed for the three-point bending tests.

Figure 3. Uniaxial compression test: “M” before(a) and after(e) ; “MH” (b, c, d) and “MS” (f, g, h) reinforced mortar specimens before (b, f), during (c, g) and after (d, h)