FRP composites for shear strengthening of reinforced concrete deep beams with openings

2009 ◽  
Vol 89 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Tamer El Maaddawy ◽  
Sayed Sherif
Keyword(s):  
Reinforced Concrete ◽  
Deep Beams ◽  
Shear Strengthening ◽  
Frp Composites

scholarly journals Shear and Flexural Behavior of Reinforced Concrete Deep Beams Strengthened with CFRP Composites

2017 ◽  
Vol 11 (10) ◽  
pp. 110 ◽  
Author(s):  
Hana Al-Ghanem ◽  
Aya Al-Asi ◽  
Mu’tasim Abdel-Jaber ◽  
Maha Alqam
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Strength ◽  
Flexural Behavior ◽  
Fiber Reinforced Polymers ◽  
Deep Beams ◽  
Carbon Fiber Reinforced Polymers ◽  
Shear Strengthening ◽  
Cross Sectional ◽  
Flexural Strengthening ◽  
Cfrp Composites

The current research studies the shear and flexural behavior of reinforced concrete (RC) deep beams strengthened with externally bonded carbon fiber-reinforced polymers (CFRP). Using two types of CFRP composites including sheets and laminates, different configurations for shear and flexural strengthening of deep beams were experimentally investigated. In total, twenty specimens of deep beams with cross-sectional dimensions of 190 mm width, 400 mm depth and an overall length of 1 900 mm were casted and tested to failure. Concerning the cracks’ formation, failure’s modes, ultimate strength and overall stiffness, the performance of the strengthened beams compared to the control beams were evaluated. From the test results, the effectiveness of CFRP technique on enhancing both the shear and flexural capacity of deep beams is verified; however, the efficiency differs variedly depending on the material and the strengthening scheme. Regarding the shear strengthening, using the continuous wrap of two sheets records the highest increase in the ultimate strength with a value exceeds 86% compared only to 36% with the inclined laminates. On the other hand, an enhancement of about 51% is achieved through the flexural strengthening with two layers of sheets and 26% when the laminates are used; both are accompanied by a divergent in the failure mode from flexure to shear. 

Elimination of Debonging of FRP Strips in Shear Strengthened Beams Using Grooving Method

2011 ◽  
Vol 250-253 ◽  
pp. 1077-1081 ◽  
Author(s):  
Davood Mostofinejad ◽  
Amirhomayoon Tabatabaei Kashani
Keyword(s):  
Reinforced Concrete ◽  
Experimental Studies ◽  
High Strength ◽  
Concrete Surface ◽  
Reinforced Concrete Beams ◽  
Small Scale ◽  
Shear Strengthening ◽  
Flexural Strengthening ◽  
Frp Composites ◽  
Frp Strips

One of the methods of retrofitting reinforced concrete structures is use of FRP sheets to increase the flexural and shear strength of concrete elements. Use of FRP materials is in rapid progress because of their high strength, light weight and easy installation of FRP composites. Poisson’s ratio mismatch between FRP sheets and concrete is resulted premature debonding of FRP strips. Hence, the use of ultimate strength of FRP sheets is difficult if EB (External bonded) is applied in installation of FRP. Therefore, debonding has been repeatedly reported in most experimental studies. Recent studies in Isfahan University of Technology (IUT) show that use of grooving method (GM) to attach the FRP sheet to concrete surface for flexural strengthening is much more effective compared to conventional methods. In present experimental study, small scale reinforced concrete beams were strengthened with FRP strips for shear. Comparison between the ultimate load and deflection of the test beams demonstrates that grooving method was effective and led to elimination of debonding of FRP strips used for shear strengthening.

In-Situ Verification of Rehabilitation and Repair of Reinforced Concrete Bridge Bents under Simulated Seismic Loads

2001 ◽  
Vol 17 (3) ◽  
pp. 507-530 ◽  
Author(s):  
Chris P. Pantelides ◽  
Janos Gergely ◽  
Lawrence D. Reaveley
Keyword(s):  
Reinforced Concrete ◽  
High Strength ◽  
In Situ Tests ◽  
Shear Strengthening ◽  
Displacement Ductility ◽  
Frp Composites ◽  
Frp Composite ◽  
Pile Cap ◽  
Bridge Bents

Three in-situ tests were performed on two bents of a reinforced concrete (RC) bridge under quasi-static cyclic loads. The bridge was built in 1963 and did not possess the necessary reinforcement details for ductile performance. The tests included an as-built bent, a bent rehabilitated with carbon fiber reinforced polymer (FRP) composite jackets, and a damaged bent repaired with epoxy injection and carbon FRP composite jackets. Two new concepts of strengthening bridge bents with FRP composites were implemented in this study. The first involves shear strengthening and confinement of a beam cap-column joint through an FRP composite “ankle-wrap.” The second is an FRP composite “U-strap” to improve the anchorage of column longitudinal steel reinforcement extending into the joint. FRP composite jackets were also implemented in the columns and beam cap. An additional rehabilitation measure was that of anchorage of the piles to the pile cap using epoxied high strength steel bars. The performance of the bent in the as-built condition and that of the rehabilitated and repaired bents is described in terms of strength, stiffness, displacement ductility, and energy dissipation.

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