Strengthening Effect of Prestressed Near‐Surface‐Mounted CFRP Tendon on Reinforced Concrete Beam

Abstract

Efforts are being made to use FRP (fiber-reinforced polymer) for reinforcements instead of traditional construction materials like steel owing to its remarkable mechanical properties. Among them, this study developed a CFRP tendon to be used as near-surface-mounted reinforcement together with a dedicated prestressing system and investigates experimentally the strengthening effect considering various variables including the amount of reinforcement, the bond performance, and the strength and damage ratio of the concrete. The test results reveal that one line of reinforcement improved the strengthening performance by about 55% and two lines by 96% and that the bonding of the CFRP tendon enhanced the strengthening performance by 15%. Higher strength and damage of the concrete seem to have a poor effect on the overall strengthening performance. However, the use of CFRP tendon with bond performance higher than 11 MPa, filler, and anchorage system appears to promote stable strengthening behavior.

Fatigue Behavior of Concrete Beam with Prestressed Near-Surface Mounted CFRP Reinforcement According to the Strength and Developed Length

“…Figure 6b shows the residual strength of the specimens after fatigue loading. The results are seen to be nearly identical to those obtained in a previous work [23] in which static loading was applied without preliminary fatigue loading. When static loading is applied without accumulation of fatigue, the load-deflection curve presents three distinct behaviors that are the crack behavior, the yield behavior and the fatigue behavior.…”

Torsional Strengthening of RC Beams with Near‐Surface Mounted Steel Bars

“…e greater confinement granted by the adhesive and the surrounding concrete is considered the best advantage provided by the NSM method [2]. is strengthening technique has already been proven to be effective for the shear strengthening [3][4][5][6] and flexural strengthening of RC beams [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Many studies have used conventional steel bars instead of FRP materials for beam strengthening by employing the NSM method [21,[23][24][25][26][27][28][29].…”

“…Many studies have applied the NSM FRP strengthening method to improve the flexural and shear strength of RC beams [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], whilst others have used conventional steel bars instead of FRP materials for flexural and shear strengthening [21][22][23][24][25][26][27][28]. However, only few of these studies have focused on torsion strengthening [29][30][31]32] and no previous work has investigated the application of conventional steel bars for the torsion strengthening of RC beams.…”

Comparative Investigation on Torsional Behaviour of RC Beam Strengthened with CFRP Fabric Wrapping and Near‐Surface Mounted (NSM) Steel Bar

“…e greater confinement granted by the adhesive and the surrounding concrete is considered the best advantage offered by the NSM method [41]. is strengthening technique has already been proven to be effective for the shear and flexural strengthening of RC beams [42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58]. Many studies have also used conventional steel bars instead of FRP materials for flexural and shear strengthening by employing the NSM method [59][60][61][62][63][64].…”