PSI - Issue 44

Rebecca Fugger et al. / Procedia Structural Integrity 44 (2023) 2166–2173 Author name / Structural Integrity Procedia 00 (2022) 000–000

2170

5

230 mm for the mortar and composite, as recommended by ASTM E519-07 (2007)). For the bare textiles, due to the impossibility of a uniform speckle pattern on the specimen surface, ΔH as the average shortening recorded between the pairs A-A' and B-B' and ΔV was evaluated as the average of the two elongations between the pairs C-C' and D-D' (Fig.3a). For the mortar and composite specimens, ΔH and ΔV were determined as the average shortening recorded from the three horizontal points (1-3) and the average extension of three vertical points (4-6), respectively. For bare textiles and mortar specimens, the shear modulus G was determined as the tangent of the ascending linear branch of the response curves, in accordance with EAD 340275-00-0104 (2020), and for composite specimens as the ratio of 0.3τ max to the corresponding shear strain, in accordance with Del Zoppo et al. (2019).

Table 1. Results of shear tests on bare textile, mortar matrix and composite specimens.

τ max [N/mm

2 ]

γ(τ

max ) [-]

G [kN/mm

2 ]

τ*

max [kN/m]

Specimen type

Test code

T9

71.7 88.0

0.284 0.220 0.003 0.001 0.012 0.010 0.006 0.006

0.28 0.43 2.61 2.23 2.64 2.31 2.09 2.77

4.59 5.63

Bare textile

T15 M-C M-L T9-C

6.6 2.4 7.0 8.6 3.3 4.4

66.43 24.16 70.10 86.27 32.90 43.86

Mortar matrix

T15-C

Composite specimens

T9-L

T15-L

3.1. Response curves and failure modes Shear stress versus strain response curves on bare textile, mortar matrix and composite specimens are shown in Fig.4. For each group of tests, the curves of the single tests and the average curves are represented.