PSI - Issue 11

Francesca Giulia Carozzi et al. / Procedia Structural Integrity 11 (2018) 355–362 F.G. Carozzi et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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Tensile tests were performed on samples composed of a single yarn extracted from the textile [Carozzi et al., 2018], [Carozzi et al, 2015]. The test were carried out using a testing machine with a maximum load capacity of 2 kN. Cardboard tabs were glued at the ends of the specimens to avoid local damage and guarantee a homogeneous stress distribution. In order to avoid a premature failure of the dry glass yarns, the samples were impregnated with a thin layer of epoxy resin. Five tests were performed for each material and the average values and the coefficient of variation are reported in Table 2. The mechanical properties of the lime mortar were investigated according to EN 1015-11 and EN 13412. The average flexural and compressive strength are equal to 3.16 MPa and 7.48 MPa respectively, and the elastic modulus was equal to 6.08 GPa. Table 2 – Reinforcement component mechanical properties Sample Tensile strength [MPa] Elastic modulus [GPa] Glass yarn 1443 (11.4%) 75.4 (6.2%)

Coated glass yarn (warp direction) Coated glass yarn (weft direction)

1233 (2.7%)

55.6 (30.5%)

1120 (1.7%)

60.5 (28.2%)

Steel bars

1110*

195*

*From data sheet

4. Tests set-up and instrumentation

Two steel shoes were placed on diagonally opposite corners of the wall and connected by two Dywidag bars creating a close-loop system. The walls were loaded diagonally by means of two parallel manual jacks positioned at the top corner on one steel shoe. Two load cells were used to measure the applied loads. Four LVDTs were located on the diagonals of the walls to measure the relative displacements; other two LVDTs were used to measure the displacement imposed by the jacks and control the homogeneous stresses distribution between the two sides of the specimen during the tests. In Fig. 3 and Fig. 4 the test set-up and the localization of the LVDTs are shown.

a b Fig. 3. Instrumentation: a)Test set-up ; b) Detail of the steel shoe and jacks