Performance of Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforced Polymer Strips

Abstract

Carbon fiber reinforced polymers (CFRP) have shown considerable potential in the repair and rehabilitation of deficient reinforced concrete (RC) structures. To date, several CFRP strengthening schemes have been studied and employed practically. In particular, strengthening of shear damaged RC members with CFRP materials has received much attention as an effective repair and strengthening approach. Most existing studies on strengthening shear-deficient RC members have used unidirectional CFRP strips. Recent studies on strengthened T-beams demonstrated that a bidirectional CFRP layout was more effective than a unidirectional layout. As such studies are limited, in this study, the feasibility of bidirectional CFRP layouts for the shear strengthening of rectangular RC beams was experimentally evaluated. Bidirectional layout details with CFRP anchors as well as rehabilitation timing were considered and investigated. The test results showed that the members with a bidirectional CFRP layout carried less shear strength capacity than those with unidirectional layouts for the same quantity of CFRP material. Nevertheless, the bidirectional CFRP layout allowed for a uniformly distributed stirrup strain compared to the unidirectional CFRP layout at the same load level, which increased the efficiency of the transverse reinforcement. Additionally, the shear contribution of CFRP material according to the CFRP strengthening timing was verified.

Theoretical and Experimental Substantiation of the Efficiency of Combined-Reinforced Glass Fiber Polymer Composite Concrete Elements in Bending

“…Finally, from a price point of view, the cost of our elements is reduced and is more economical, as confirmed by our economic analysis. This is in good agreement with the results of the authors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]35,[37][38][39][40][41][42][43][44][45][46][47][48][49][50].…”

“…Our results showed a higher bearing capacity and especially in combination with the fact that the mass of our elements is less than sim- Next, consider the constructive effect we have achieved, it consists of improving the performance of an improved design due to the synergistic effect of fiber reinforcement of bending elements and in combination of such dispersed reinforcement with polymer composite reinforcement with rods. In this regard, our results seem to be effective in comparison with the results of the authors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Our results showed a higher bearing capacity and especially in combination with the fact that the mass of our elements is less than similar reinforced concrete elements.…”

“…Next, consider the constructive effect we have achieved, it consists of improving the performance of an improved design due to the synergistic effect of fiber reinforcement of bending elements and in combination of such dispersed reinforcement with polymer composite reinforcement with rods. In this regard, our results seem to be effective in comparison with the results of the authors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Our results showed a higher bearing capacity and especially in combination with the fact that the mass of our elements is less than sim- Next, consider the constructive effect we have achieved, it consists of improving the performance of an improved design due to the synergistic effect of fiber reinforcement of bending elements and in combination of such dispersed reinforcement with polymer composite reinforcement with rods.…”

“…The improvement of reinforced concrete bending elements is the most relevant at the present time and has already been considered in many studies, for example, in [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. In this case, various improvement methods are used: reinforcement with polymer composite materials [2,5,8,[10][11][12][13]15,16], various fibrous materials [6,9,14], Fe-SMA activation [3], and cathode-ray tubes made of glass waste [7]. The economic aspect was also considered-the cost of reinforced concrete beams largely depends on the brand of reinforcing steel [1].…”

Maintenance and Inspection of Fiber-Reinforced Polymer (FRP) Bridges: A Review of Methods

“…Some studies have reviewed the types of FRP applications in reinforced concrete structures [8][9][10][11][12]. Flexural application means that the boards, strips and fabrics of FRPs are pasted on a simply supported beam.…”