PSI - Issue 37

Ghusoon S. Alshami et al. / Procedia Structural Integrity 37 (2022) 367–374 Alshami et al./ Structural Integrity Procedia 00 (2021) 000 – 000

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2. Research Objective and Significance Many studies were carried out to investigate and prove the effectiveness of using FRP systems in strengthening new and existing concrete structures. Some studies have proven that anchoring FRP laminates delay debonding and strengthen the structure. Strengthening of concrete structures using FRP reinforcement and anchors enhanced the capacity, durability, and economical value of such structures. The objective of this research study is to conduct bending tests on strengthened concrete prisms to investigate the effect of anchoring CFRP laminates on small scale concrete beams with different CFRP anchor embedment depths. Furthermore, this research will compare the load deflection response curves of CFRP strengthened and anchored specimens with that of control unstrengthened and unanchored specimens. In addition, it will compare the maximum attained strains in the laminates between anchors and unanchored specimens. The test results will also examine the effect of anchor embedment depth on the capacity of the concrete prisms. The literature still lacks comprehensive information on the effect of different anchor parameters such as embedment depth of anchors on the performance of the anchorage system. Thus, this study will focus on the effect of spike anchors embedment depth on the performance of strengthened concrete prisms. However, more research should be conducted to cover the effect of other parameters on RC beams. 3. Experimental Program 3.1 Test Matrix The experimental program consisted of six concrete prisms. All prisms have a total length of 750 mm and cross section of 150 x 150 mm. To ensure flexural cracking at mid-span, a 25 mm notch with width of 3 mm was cut at the bottom midspan of the prisms. Figure 1 shows the prisms detailing. One prism was left unstrengthened (C), and one was strengthened with one unanchored layer of CFRP laminate (L1) to act as benchmark specimens. In addition, four prisms were strengthened with CFRP laminates and anchored with spike anchors. The laminates that were bonded to the prisms’ soffit had a total length of 550 mm and width of 100 mm. All anchors had a diameter of 10 mm, insertion angle of 90º and fan length and width of 100 mm as shown in Fig. 2. The main parameter investigated in this study was the anchor embedment depth. Four embedment depths (h emb ) of 50, 75, 100, and 125mm are varied in this study. The p rism’ s designations and detailing are also provided in Table 1.

Fig.1. Concrete prisms detailing.

Fig2. Anchor parameters of strengthened prisms. (a) Front view; (b) Bottom view