PSI - Issue 47

Shakiba Zolfaghari et al. / Procedia Structural Integrity 47 (2023) 398–407 S. Zolfaghari et al./ Structural Integrity Procedia 00 (2019) 000–000

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and Table 4). At the groove width of 15 mm (groove depths of 5, 10, and 15 mm), with the increase of the groove depth from 5 to 10 mm, the debonding load increased slightly from 11.15 to 11.20 kN (i.e., it remained almost constant) and then by increasing the groove depth to 15 mm, it increased to 12.3 kN. That is, the optimum groove depth corresponding to the groove width of 15 mm should be 15 mm. Given that the groove volume in the specimen EBROG-15×15 is 3 times the volume of the groove in the specimen EBROG-15×5 and the debonding load increases 10.3%, the optimum groove depth corresponding to the groove width of 15 mm can be considered 5 mm (Fig. 5(d) and Table 4).

Groove width = 2.5 mm

Groove width = 5 mm

8,5 9 9,5 10 10,5

15

10,1

11,98

10,27

9,94

9,7

10

9

5

0

0

2

4

6

8

0

5

10

15

20

Debonding load (kN)

Debonding load (kN)

Groove depth (mm)

Groove depth (mm)

(a)

(b)

Groove width = 10 mm

Groove width = 15 mm

12,3

15

12,5

11,67

10,54

9,33

10

12

5

11,5

11,15 11,2

0

11

0

5

10

15

20

0

5

10

15

20

Debonding load (kN)

Debonding load (kN)

Groove depth (mm)

Groove depth (mm)

(c)

(d)

Fig. 5. Effect of groove depth variation on the FRP-concrete bond debonding load: (a) groove width = 2.5 mm; (b) groove width = 5 mm; (c) groove width = 10 mm; (d) groove width = 15 mm.

4. Conclusions In this study, by conducting single-lap shear tests on EBR and EBROG specimens, the effect of changes in the width and depth of the groove on the FRP-concrete bond behavior was investigated, and the two approaches of the maximum load and the debonding load were discussed in determining the bond strength and the following results were obtained:  The EBROG method increased the bond maximum load by 14.7-73.5% and the debonding load by 12.5-53.7% compared to the EBR method and showed its power and superiority in delaying the separation phenomenon.  From the maximum load point of view, the specimen EBROG-10×5 with a maximum load of 14.40 kN is considered as the specimen with the optimal groove dimensions. From the debonding load point of view, having