PSI - Issue 28

Jamal A. Abdalla et al. / Procedia Structural Integrity 28 (2020) 2312–2319 Author name / Structural Integrity Procedia 00 (2019) 000–000

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deflection curves of the tested beams and Figure 6 shows the modes of failure of the tested beams. All beams failed in flexure.

Table 3. Ultimate load, deflection and failure modes for beams Label Ultimate

Failure Mode

Maximum Deflection (mm)

Increase in Ultimate Load over Control (%)

Deflection ratio over Control (%)

Load (kN)

Control

179.9

20.1

-

-

Pure flexural failure, yielding in Steel then followed by concrete crushing

CFRP

247.7 231.1

12.6 19.8

37.69 28.46

62.7 98.5

Concrete crushing and CFRP de-bonding

SMH+AA

Steel yielding then followed by hybrid (SMH+AA) delamination (concrete cover separation) Steel yielding followed by hybrid (CFRP+AA) de bonding

CFRP+AA

229.2

11.3

27.40

56.2

300

250

200

150

100 Load (kN)

Control CFRP SMH+AA CFRP+AA

50

0

0

5

10

15

20

25

Deflection (mm)

Fig. 5. Load deflection relationship It is also clear that beams that were strengthened with FRP sheet attached to the concrete face then AA plate to the outer side provided high flexural capacity, though better deformation values than other groups compared to control beam without strengthening materials.

(a) Control

(c) SMH+AA

(b) CFRP+AA

Fig. 6. Failure modes; (a) failure mode of control, (b) failure mode of CFRP+AA (c) failure mode of SMH+AA