PSI - Issue 64

Sadeq Mo. Annooz et al. / Procedia Structural Integrity 64 (2024) 1565–1572 Annooz, Williams, and Myers / Structural Integrity Procedia 00 (2024) 000–000

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a

b Figure 2. (a) BFRP rebars sleeved with PVC tubes. (b) The specimens in the curing room.

3. Experimental work The pullout test was conducted using a universal machine with a capacity of 890 KN (200 kips). The specimen was flipped, and the free end of the rebar was fed through the machine. The concrete part of the specimen was seated on top of the machine on a 5-cm (2 in.). rubber pad to ensure that the specimen was seated evenly and a uniform load distribution was applied, as shown in Figure 3.

Notes: Figure shown for 19 mm bar test. 5d b =95 mm for 19 mm dia bar. 5d b =65 mm for 13 mm dia. bar.

Figure 3. Test set up.

The free end of the rebar was fed into the universal machine’s wedge-shaped grips. A small amount of pressure was applied manually on the grips; then, continuous pressure was applied due to the tension force and the wedge shape of the grips as soon as the test began. A linear variable differential transformer (LVDT) was used to record the slippage in the rebar; the LVDT was seated on top of the rebar. A loading rate of 0.25 mm/min. (0.01 in./min.) was used (Al Khafaji et al. 2021). A tension load was applied to the specimens till after 50% of the peak point. 4. Test Result and Discussion The steel rebar specimens resulted in a splitting failure, as shown in Figure 4, while all BFRP rebar specimens resulted in a pullout failure, as shown in Figure 5. The splitting failure mode is believed to be related to the concrete's compressive strength relative to its design strength of 35 MPa (5 ksi) and improved bond behavior due to the bar lug pattern.