Shear Behaviour of RC Beams Strengthened with FRP Materials

2012 ◽  
Vol 463-464 ◽  
pp. 249-253
Author(s):  
Jiang Feng Dong ◽  
Dong He ◽  
Shu Cheng Yuan ◽  
Qing Yuan Wang
Keyword(s):  
Concrete Strength ◽  
Research Work ◽  
Shear Behaviour ◽  
Rc Beams ◽  
Test Results ◽  
Shear Strengthening ◽  
Four Point Bending ◽  
Reinforced Polymer ◽  
Externally Bonded ◽  
Glass Frp

This paper reports the results of a research work aimed at examining the use of externally bonded of fiber reinforced polymer (FRP) sheets, consisting of carbon FRP (CFRP) and glass FRP (GFRP), as a strengthening solution to upgrade the shear capacities of reinforced concrete (RC) beams. A total of 7 RC beams were constructed and tested under four-point bending, i.e. two reference beams with different concrete strength and without any FRP sheets, one beam reinforced by GFRP sheets and four beams reinforced by CFRP sheets. Externally bonded FRP shear strengthening was found very effective in upgrading the shear strength of the beams strengthened. The shear strengths of RC beams strengthened were improved greatly by FRP sheets, and the strength gain caused by the FRP sheets was in the range of 31-74%. Test results also show that the more ductile behaviour and higher ultimate strength are obtained for the beams with FRP shear strengthening by using high concrete strength.

FINITE ELEMENT MODELLING OF 2-SPAN CONTINUOUS RC BEAMS SHEAR STRENGTHENED AND SHEAR REPAIRED WITH CFRP STRIPS

2016 ◽  
Vol 78 (5) ◽  
Author(s):  
Abdul Aziz Abdul Samad ◽  
Noorwirdawati Ali ◽  
Noridah Mohamad ◽  
J. Jayaprakash ◽  
Tuan Duc Ngo ◽  
...  
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Shear Behaviour ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Existing Structures ◽  
Finite Element Software ◽  
Externally Bonded ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

Strengthening of reinforced concrete (RC) continuous beams in shear have received very little attention among researchers even though most existing structures are in the form of continuous condition such as part of a floor-beam system. Therefore, in order to address the gap, a study on shear strengthening and shear repair of reinforced concrete continuous beam using Carbon Fibre Reinforced Polymer (CFRP) strips was conducted [15].  The validation of the experimental results was conducted with a simulation study using a finite element software ATENA v4 [16].  The research variables were number of layers of CFRP strips (one or two layers), wrapping schemes (four sides or three sides) and orientation of CFRP strips (0/90 or 45/135 degree’s). From the analysis of the finite element results, ATENA shows it has successfully simulated the shear behaviour of strengthened and repaired of 2-span continuous RC beams externally bonded by CFRP strips. 

scholarly journals Shear Strengthening Performance of Hybrid FRP-FRCM

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Kyusan Jung ◽  
Kinam Hong ◽  
Sanghoon Han ◽  
Jaekyu Park ◽  
Jaehyun Kim
Keyword(s):  
Shear Capacity ◽  
Shear Strengthening ◽  
Cementitious Matrix ◽  
Reinforced Polymer ◽  
Capacity Model ◽  
Proposed Model ◽  
Externally Bonded ◽  
Strengthened Beam ◽  
Fabric Reinforced Cementitious Matrix ◽  
Glass Frp

The effectiveness of a hybrid fiber reinforced polymer- (FRP-) fabric reinforced cementitious matrix (FRCM) for shear strengthening was investigated though an experimental study. FRP materials of FRCM are usually fabricated in the form of a fabric to enhance the bond strength between the FRP material and the cementitious matrix. The hybrid FRP fabric used in this study consisted of carbon FRP (CFRP) and glass FRP (GFRP) in warp and weft directions, respectively. A total of 11 beams were fabricated and 8 beams among them were strengthened in shear with externally bonded hybrid FRP-FRCM. The number of plies, the bond types, and the spacing of the hybrid FRP fabric were considered as experimental variables. Additionally, a shear capacity model for a FRCM shear strengthened beam was proposed. The values predicted by the proposed model were compared with those by the ACI 549 code and test results. It was confirmed from the comparison that the proposed model predicted the shear strengthening performance of the hybrid FRP-FRCM more reliably than the ACI 549 code did.

scholarly journals Effect of Preload Level on Flexural Load-carrying Capacity of RC Beams Strengthened by Externally Bonded FRP Sheets

2015 ◽  
Vol 9 (1) ◽  
pp. 426-434 ◽  
Author(s):  
Guibing Li ◽  
Aihui Zhang ◽  
Yugang Guo
Keyword(s):  
Carrying Capacity ◽  
Concrete Strength ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Test Results ◽  
Damage Level ◽  
Cfrp Sheets ◽  
Flexural Performance ◽  
Load Carrying ◽  
Externally Bonded

Most of the laboratory tests investigated the flexural performance of un-preloaded or undamaged RC beams strengthened with CFRP composites. However, in engineering applications, the structural member must carry a certain load or damage. There is a lack of systematical investigations on the effects of preload or damage level on the flexural load-carrying capacity of CFRP-strengthened RC beams. This paper tested 22 RC beams to investigate the influence of preload level on flexural load-carrying capacity of CFRP-strengthened RC beams. The test variables are preload level, amount of CFRP sheets, tension rebar ratio, and concrete strength. The test results show that if the preload level is not more than 80% of the yielding strength of the original beam, the preload or damage level does not influence the flexural load-carrying capacity of CFRP-strengthened RC beams. However, the ultimate flexural load-carrying capacity is significantly poor than that of RC beam strengthened under a preload level not more than 80% of the yielding strength, if the RC beams are strengthened under a preload level more than 90% of the yielding strength.

scholarly journals In-plane Shear Strengthening of Unreinforced Masonry Walls Using GFRP Jacketing

2017 ◽  
Author(s):  
Enea Mustafaraj ◽  
Yavuz Yardim
Keyword(s):  
Experimental Results ◽  
Test Results ◽  
Compression Tests ◽  
Shear Strengthening ◽  
Plane Shear ◽  
Standard Size ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Diagonal Compression ◽  
Before And After

In this paper, it is presented the experimental results of a campaign on diagonal compression tests, as of ASTM E519-02, to assess and compare the in-plane behavior of standard size of 1200 × 1200 × 250 mm, for three unreinforced and three reinforced wall panels by glass fiber reinforced polymer (GFRP) embedded in an inorganic matrix.From the diagonal compression test results, were determined some of the main mechanical parameters such as: shear strength, modulus of rigidity and ductility, before and after application of the reinforcement.The experimental results showed that the GFRP reinforced panels exhibited a significant increase of 127% in shear resistance, 1100% in ductility and 650% in modulus of rigidity when compared to unreinforced panels.It was concluded that this technique provided satisfactory results and can be considered a suitable method for repair of masonry structures.

EFFECT OF WET-DRY CYCLING ON BOND BEHAVIOR OF GFRP STRENGTHENED HISTORIC MASONRY STRUCTURES

2016 ◽  
Vol 78 (5-2) ◽  
Author(s):  
Meng Jing ◽  
Werasak Raongjant
Keyword(s):  
Research Work ◽  
Fiber Reinforced Polymer ◽  
Masonry Structures ◽  
Test Results ◽  
Bond Behavior ◽  
Historic Masonry ◽  
Water Permeation ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Cycling Condition

The objective of this research work is to determine the effect of wet-dry cycling on bond behavior of historic masonry structures strengthened by Glass Fiber Reinforced Polymer (GFRP). Shear bond testing was carried out through total 36 specimens exposed to dry, full moisture or wet-dry cycling conditions.  The selected samples were then tested at 0, 30, 60 and 90 days. Post-ageing test was also preceded on total sixty masonry prisms exposed to dry, full moisture or wet-dry cycling conditions. The compressive strengths of selected samples were then tested at 0, 40, 70 and 100 days. The test results showed an obvious decrease of the bond strength between GFRP sheets and bricks in the wet-dry cycling condition. For masonry prisms with or without GFRP strengthening, in the first 40 days, the compressive strength of GFRP bonded prism decreased quickly to the value near that of prism without GFRP. After 40 days the rate of decrease became slow, which means that, sheets retrofitted outside the masonry prisms helped to improve their durability by reducing water permeation. 

scholarly journals Strengthening of self-compacting reinforced concrete deep beams containing circular openings with CFRP

2018 ◽  
Vol 162 ◽  
pp. 04015
Author(s):  
Nabeel Al-Bayati ◽  
Bassman Muhammad ◽  
Murooj Faek
Keyword(s):  
Ultimate Load ◽  
Test Results ◽  
Load Path ◽  
Deep Beams ◽  
Self Compacting Concrete ◽  
Reinforced Polymer ◽  
Web Reinforcement ◽  
Externally Bonded ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper shows the behavior of reinforced self-compacting concrete deep beams with circular openings strengthened in shear with various arrangements of externally bonded Carbon Fibre Reinforced Polymer (CFRP). Six simply supported deep beams were constructed and tested under two points load up to the failure for this purpose. All tested beams had same geometry, compressive strength, shear span to depth ratio, main flexural and web reinforcement. The variables considered in this study include the influence of fiber orientation, utilizing longitudinal CFRP strips with vertical strips and area of CFRP. The test results indicated that the presence of the circular openings in center of load path reduce stiffness and ultimate strength by about 50% when compared with solid one, also it was found that the externally bonded CFRP can significantly increase the ultimate load and enhance the stiffness of deep beam with openings.

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