PSI - Issue 54

Rami A. Hawileh et al. / Procedia Structural Integrity 54 (2024) 287–293 Hawileh et al./ Structural Integrity Procedia 00 (2019) 000 – 000

291

5

(b)

(c)

Fig. 2. Failure mode of specimens; (a) BU; (b) A2; (c) A4

3.2. Load-deflection curves The load versus midspan deflection of the tested beams is shown in Fig. 3. The load-deflection plots are compared to the unanchored beam. In the case of the strengthened unanchored specimen (BU), the load showed a sudden drop at a maximum deflection of 10.1 mm after reaching the ultimate state. This implies that the ductility of the RC beam is lost as a result of strengthening using the CFRP, which was evident in the brittle failure mode of this beam in the form of sudden delamination. Regarding anchored specimens, a slight increase in the ultimate load is portrayed by specimen A2 (12%) compared to specimen BU, with a negligible increase in the maximum deflection as shown in Fig. 3. For the same embedment depth and fan length, adding one anchor slightly increased the ultimate capacity of the beam. Nevertheless, specimen A4 exhibited a considerably higher maximum deflection value compared to specimens A2 and BU. This can be attributed to the contribution of the FRP anchors in preventing the sudden detachment of the FRP sheet from the concrete beam which allowed the beam to deflect gradually as the load increases.

100 120 140 160

A2 A4 BU

0 20 40 60 80

Load (kN)

0

5

10

15

20

Midspan deflection (mm)

Fig. 3. Load versus midspan deflection curves