Issue 74

V. J. Kalyani et alii, Frattura ed Integrità Strutturale, 74 (2025) 89-114; DOI: 10.3221/IGF-ESIS.74.07

the specimens are cleaned to remove surface debris. The top and bottom surfaces of the specimen are smoothened using an electric grinding machine to eliminate surface irregularities and weak concrete as illustrated in Fig. 5(d). Subsequently, they are cleaned using cloth and an air blower. The two parts of the dumbbell specimen are positioned in place, and a layer of epoxy adhesive is applied uniformly to the bonding surface. A 500 mm × 100 mm laminate is placed over the adhesive layer and compacted using a specialized hand roller to ensure proper adhesion and removal of air voids. Another layer of epoxy is applied over the first laminate, followed by the placement and rolling of the second laminate layer. A final layer of adhesive is then applied over the second laminate as shown in Fig. 5(e). After 24 hours of ambient curing, the specimen is turned over, and the same procedure is repeated on the opposite face. Additional fabric layers, as per the requirement for three layers strengthening, are applied in the same sequence on both sides. After strengthening, the specimens are allowed to cure under ambient conditions for 7 days before testing. A typical specimen ready for testing is shown in Fig. 5(f).

Sikadur 30 LP Sikadur 330 No. of Specimens No. of Specimens

Sr. No.

Specimen Configuration

Description of material used

1

GG

Two layers of GFRP

3

3

2

GS

One layer of GFRP and one layer of SSWM with SSWM on top

3

3

3

SG

One layer of SSWM and one layer of GFRP with GFRP on top

3

3

4

SS

Two layers of SSWM

3

3

5

GGG

Three layers of GFRP

3

3

6

GSG

Two layers of GFRP with one layer of SSWM between them

3

3

7

SGS

Two layers of SSWM with one layer of GFRP between them

3

3

8

SSS

Three layers of SSWM

3

3

TOTAL

48

Table 3: Different strengthening configurations for bond test.

(all dimensions are in mm) (a)

(b)

(c)

95