PSI - Issue 44

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

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Fig. 1. Basalt textile (a) with grid-spacing of 9mmx9mm; (b) of 15mmx15mm and (c) composite specimen.

Fig. 2. (a) Setting the PLA formwork; (b) cast of first layer of lime-mortar; (c) setting the textile layer; (d) cast of the second layer of lime-mortar and (e) specimen provided with speckle pattern.

2.1. Materials Tested FRCM systems were made of a bidirectional balanced basalt open mesh embedded within either a lime based or cement-based mortar matrix. The textiles consisted of a bidirectional balanced open mesh basalt yarns (Fig. 1a), with mass density of about 400g/m 2 and equivalent thickness t f =0.064mm, but with different grid spacing. Both of them have two stainless-steel micro-wires next to each yarn, in order to facilitate installation and application in the field. More specifically, the textiles and the matrices have the following geometric and mechanical characteristics:  T9: grid spacing of 9mmx9mm and a cross section of the single yarn 0.58 mm 2 . The average tensile strength is equal to 1117N/mm 2 (coefficient of variation CV = 4.5%) and tensile modulus of elasticity equal to 61kN/mm 2 (CV = 4.0%);  T15: grid spacing of 15mmx15mm and a cross section of the single yarn 0.96 mm 2 . The average tensile strength is equal to 1554N/mm 2 (CV=4.9%) and tensile elasticity modulus is 74kN/mm 2 (CV=2.2%);  M-L: lime-based mortar which includes natural hydraulic lime, natural kaolin (hydrated aluminium silicate), and bauxite. It is classified as M15 according to UNI EN998-1 (2016) where the average tensile strength is equal to 4.9N/mm 2 (CV=2.6%), average compressive strength equal to 16.87kN/mm 2 (CV=7.88%) and Young’s modulus of 4.9 kN/mm 2 (CV=16%), determined in accordance with EN1015-11 (2019) guidelines;  M-C: cement-based and fibre-reinforced mortar. The average tensile strength is equal to 8.7N/mm 2 (CV=15.3%), compressive strength of 62.5N/mm 2 (CV=12.1%) and Young’s modulus of 11.2kN/mm2 (CV=15.3%) determined in accordance with UNI EN998-1 (2016) and EN1015-11 (2019) guidelines. 2.2. Testing set-up An innovative setup made of a four-hinge frame was designed in order to perform shear tests. Shear loading is due to the vertical pulling of the frame at the bottom in the vertical direction, which induces an horizontal compression. The yarns composing the textile mesh are oriented at 45° to the horizontal direction Fig. 3a. Tests were carried out