PSI - Issue 78

Teklewoin Haile Fitwi et al. / Procedia Structural Integrity 78 (2026) 1775–1782

1777

9.88% elongation as illustrated in Fig. 2(a). Further, the damaged concrete surface was restored using a cementitious repair mortar exhibiting compressive strength of 20.67 MPa and flexural strength of 6.90 MPa at 28 days. The properties of both carbon and basalt fibers are shown in Table 1.

Table 1. Geometrical and mechanical properties of the employed fabrics. Property Carbon

Basalt

Image

Tensile strength Elastic modulus

4900 MPa

>3200 MPa

240 GPa

90 GPa

Elongation at break

1.8%

>3%

155 g/m 2 155 g/m 2 30x30 mm

Weight (Warp) Weight (Weft)

109 g/m 2 109 g/m 2 15x15 mm

Mesh size

Equivalent thickness

0.60

0.56

3. Test setup and instrumentation The employed experimental test setup is illustrated in Fig. 1. The vertical loading system consisted of a hydraulic actuator (600 kN) mounted at the column top, enabling precise control of axial loading conditions throughout testing. Considering the varying concrete properties, to maintain similar axial load ratios ( = / · ) across all specimens, an axial load of 200 kN was applied to Specimens 1 and 2, while an increased axial load of 282 kN was applied to Specimen 3. Regarding the horizontal loading system, a horizontal actuator with 150 kN capacity and ±150 mm stroke range, installed at 3640 mm height from the base hinge, facilitated the application of the displacement controlled cyclic loading, simulating seismic demand conditions. The lateral loading protocol (Fig. 2b) followed ACI 374.1-05 (2019), with fourteen displacement amplitudes ratios.

Fig. 1. Test set-up: (a) schematic representation; (b) experiment.