PSI - Issue 64

Ivan Markovic et al. / Procedia Structural Integrity 64 (2024) 1621–1627 Author name / Structural Integrity Procedia 00 (2019) 000–000

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of distributed temperature or strain measurements, by means of appropriate calibration methos given in e.g. (Rodriguez et al. 2015, 2019). For the cement, a Portland cement CEM II/B-M 42.5 was used. The superplasticizer used was Master Ease 5001 from the company Sika. The reinforcement was a normal reinforcing steel B500B (with properties according to the Swiss code SIA 262). The achieved concrete strength class was C 30/37. Quick setting cement mortar PCI from Sika with standard mixing proportions was used for filling the grooves with optical cables in them. 4. Bending tests: comments and selected results of the measurements In this chapter, a selection of important and interesting results of the bending tests is made and those results are commented. In Figure 2, as example, the results of bending tests on beam specimen number 2, loaded by three-point bending, compared with the results of a non-linear FE-simulation in ATENA and with analytical modeling, are shown in three different load levels.

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Fig. 2. Left: Results of 3-point bending tests on beam specimen Nr. 2, compared to non-linear ATENA FEM-Calculation and to simple analytical model; Right: loading scheme of 3-point bending test, all measurements in [mm] Generally, the crack detection and crack localization of flexural cracks on specimens 1 to 4 works very well with the DFOS (Figure 3).

Right fibre optic cable

Strain (  m / m)

Position in optic fibre

Position in optic fibre

Fig. 3. Measured strains by internal and external DFOS Cables along the whole beam, on the left and on the right hand side of the beam at increasing load levels (diagrams bottom to top from 6 kN to 25.6 kN), showing larger strains at external DFOS