PSI - Issue 64

Nima Kian et al. / Procedia Structural Integrity 64 (2024) 1049–1056 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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resembled the columns constructed with compliance of the Turkish Seismic Design Code (1975), namely code compliant column (C). The other two columns were deliberately designed such that to resemble the substandard columns not complying the Turkish Seismic Design Code (1975). One of them was tested as substandard specimen without any retrofitting (denoted as S) while the other specimen was retrofitted with one ply of CFRP sheet wrap (denoted as RS). Table 1 shows the specimens matrix. The geometry and reinforcement details of the specimens are shown in Figure 1. Also, all reinforcements were deformed bars. The hook angle for the S and RS specimens are 90 degrees while specimen C has a hook angle of 135 degrees.

Table 1. Specimens matrix. Specimen Detail C

1975-Code-Compliant Substandard One ply of CFRP

S

RS

100

100

Lateral Load Direction

Lateral Load Direction

300

300

20

20

300

300

1000

1000

10 Ø16 Ø10 @80

10 Ø16 Ø10 @250

250

A

A

B

B

Section (A-A)

Section (B-B)

All reinforcements inside the foundation are Ø14

80

160

190

700

700

190

160

1200

1200

Fig. 1. Reinforcement details of specimens.

Table 2 shows the material properties of the reinforcements and concrete. Concrete compressive strength at around the day of cyclic tests (90 th day) , longitudinal and transverse bars’ yielding stresses, and longitudinal and transverse bars’ elastic moduli are shown as − , , , , and , respectively. The technical properties of the CFRP sheet obtained from the manufacturer are given in Table 3. Table 2. Material properties. ′ − (MPa) (MPa) (MPa) (MPa) (MPa) C 19.5 324 361 2.15×10 5 2.11×10 5 S and RS 10.5 324 361 2.15×10 5 2.11×10 5 Table 3. Mechanical properties of CFRP sheet. Property Quantity Modulus of elasticity (MPa) 240000 Maximum elongation (%) 1.8 Characteristic tensile strength (MPa) 4200 Unit weight (kg/m 3 ) 1.82 Effective thickness per ply (mm) 0.166 Specimens were tested under the constant axial load equal to 709 kN. Axial load ratio has been calculated using Equation 1. In this equation, P is the axial load applied to the column. = − × ×ℎ (1)