PSI - Issue 64

J.A.O. Barros et al. / Procedia Structural Integrity 64 (2024) 833–840 Barros et al. / Structural Integrity Procedia 00 (2019) 000 – 000

836

4

a)

b)

Fig. 3. Geometry of a) CutInov CFRP bars (SG-Strain Gauges); and b) S&P C-Anchors.

2.2. Properties of the materials By testing 3-cylinder specimens at 180 days of age (when the beams were tested) according to NP EN 12390 – 3:2011 and NP EN 12390 – 13:2014, an average compressive strength of 32 MPa and an average Young’s modulus of 28.1 GPa were obtained. Steel bars of 6-, 10-, and 16-mm diameter (  ) were adopted as reinforcements of the tested beams. By executing tensile tests according to NP EN ISO 6892-1:2016, an average yield stress was obtained for these bars: 627 MPa for the  6 mm; 531 MPa for the  10 mm; 542 MPa for the  16 mm. The tensile properties of the CutInov CFRP bars were assessed by performing tensile tests following the ISO 527-5 recommendations. An average modulus of elasticity of 150 GPa, an average ultimate tensile strength of 2382 MPa, and an average ultimate strain of 19.3‰ were obtained. 2.3. Strengthening procedures The main strengthening steps of 3CI and 3CI_A beams are shown in Fig. 4. Before the application of CutInov bars on the beams, strain gauges (SG) were installed on the surface of these bars according to the schematic representation in Fig. 2. The holes and grooves were first executed according to the predefined plan (Fig. 4.1). In the inclined parts, the holes have completely crossed the section. After cleaning the holes and grooves with compressed air, the grooves were then filled with epoxy S&P 220 HP up to 20 – 30 mm of the holes (Fig. 4.2). The bars were then installed in their final position (Fig. 4.3), with their horizontal part (NSM) involved by the epoxy and cured to attain a hardened state. The holes were then filled with epoxy S&P 55 (Fig. 4.4). For the installation of the S&P C-Anchors, holes of 14 mm diameter and 100 mm depth were executed at approximately 45 mm from the transition zone of the CutInov bars (Fig. 2c, Fig. 4.6). To avoid stress concentration on the borders of the holes and on the edges of the cross-section covered by the fan, these borders were rounded with a radius higher than 30 mm (Fig. 4.6 and 4.7). The holes were cleaned