Shear Strengthening of Reinforced Concrete T-Beams Using Anchored CFRP Materials

Shear behavior of full-scale reinforced concrete T-beams strengthened with CFRP strips and anchors

“…The a/d ratio was selected based on findings of a previous study [23], which demonstrated limited benefits from CFRP strengthening at a/d ratios below 2.0. Test specimens were strengthened in shear by externally applying CFRP fibers in strips that were wrapped around the web and anchored using CFRP anchors just below the flange of the T-beams.…”

“…Although there have been numerous experimental studies on shear strengthening using FRP materials, relatively few included mechanical anchorage of external FRP to concrete members, and even fewer used CFRP anchors (e.g., [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]). Moreover, many previous experimental studies were conducted on specimens that might not represent typical construction practices, such as small-scale specimens, specimens without transverse steel reinforcement, or specimens completely wrapped with FRP [24].…”

“…CFRP anchors have been proven to develop the full strength of externally applied CFRP strips in shear strengthening applications [18]. In a previous experimental program conducted by Kim et al [23], 610 mm deep reinforced concrete T-beams were strengthened in shear using U-wrapped CFRP strips and CFRP anchors. In most cases, CFRP anchors prevented detachment of U-wrapped CFRP strips from the beams and anchored CFRP strips were able to increase the shear strength by up to 40%; but only for beams with a shear-span (a) to effective depth (d) ratio exceeding two (a/d = 2.1 and 3.0).…”

Full-range FRP failure behaviour in RC beams shear-strengthened with FRP wraps

“…However, often the failure of RC beams shear strengthened with FRP wraps (Jirawattanasomkul et al, 2013; and in some cases with FRP U-jackets [e.g. FRP U-jackets with anchorage (Chen et al, 2016;Kim et al, 2014;Mofidi et al, 2012)], are due to the rupture of FRP, usually preceded by FRP debonding (Cao et al, 2005;.…”

“…An additional merit of the closed-form solution is that it can be directly employed in investigating the effect of shear interaction on the shear strength of FRP shear-strengthened RC beams where FRP rupture failure governs. It should be noted that although the solution is developed specifically for FRP wraps, it is also applicable to other FRP shear-strengthening schemes failing by FRP rupture, such as RC beams shear-strengthened with well-anchored FRP U-strips (Chen et al, 2016;Kim et al, 2014;Mofidi et al, 2012). In the following sections, the basic assumptions of the solution is first presented, followed by solutions for different stages during the failure process which are then validated by comparing the predictions of the solutions with finite element (FE) predictions.…”