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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mm, it decreased to 9.52 kN. That is, the optimum groove depth corresponding to the groove width of 2.5 mm is 5 mm (Fig. 2(a) and Table 3). At the groove width of 5 mm (groove depths of 5, 10, and 15 mm), with the increase of the groove depth from 5 to 10 mm, the bond maximum load increased from 11.09 to 12.66 kN and then by increasing the groove depth to 15 mm, it decreased to 11.28 kN. That is, the optimum groove depth corresponding to the groove width of 5 mm is 5 mm (Fig. 2(b) and Table 3). At the groove width of 10 mm (groove depths of 5, 10, and 15 mm), with the increase of the groove depth from 5 to 10 mm, the bond maximum load decreased from 14.4 to 10.75 kN and then by increasing the groove depth to 15 mm, it remained almost constant. That is, the optimum groove depth corresponding to the groove width of 10 mm is 5 mm (Fig. 2(c) and Table 3). 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 bond maximum load decreased from 12.86 to 12.08 kN and then by increasing the groove depth to 15 mm, it increased to 13.5 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 maximum load increased by less than 5%, considering the groove depth of 15 as the optimum depth for the groove width of 15 mm does not seem economical and logical. Therefore, the optimum groove depth corresponding to the groove width of 15 mm is considered 5 mm (Fig. 2(d) and Table 3). According to Figure 3, increasing the width of the groove compared to the depth of the groove has a greater effect on increasing the bearing capacity of the FRP-concrete joint.

Fig. 3. Effect of groove width and depth on the FRP-concrete bond performance in a groove with the same cross-sectional area. (G-b g ×h g shows the groove with the width of b g and the depth of h g .)

Table 4. FRP-concrete bond debonding load in kilonewtons for different dimensions of the groove.

2.5

5

10

15

b g (mm)

h g (mm)

2.5

9.70

-

-

-

5

10.10

10.27

11.67

11.15

7.5

9.00

-

-

-

10 15

- -

11.98

9.33

11.20 12.30

9.94

10.54

(b g : groove width; h g : groove depth)

If the debonding load is considered as the second approach to the bond strength, the results can be described as follows: