Shear behavior of reinforced concrete beams strengthened in flexure with bonded carbon fibre reinforced polymers laminates

2005 ◽  
Vol 32 (5) ◽  
pp. 812-824 ◽  
Author(s):  
Francesco Bencardino ◽  
Vincenzo Colotti ◽  
Giuseppe Spadea ◽  
Ramnath Narayan Swamy
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Shear Behavior ◽  
Structural Performance ◽  
Rc Beams ◽  
Shear Reinforcement ◽  
Brittle Behavior ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

The aim of this paper is to clarify the structural performance of reinforced concrete (RC) beams with weak or without any internal shear reinforcement and externally strengthened in flexure with carbon fibre reinforced polymer (CFRP) laminates, when subjected to a shear-dominant-loading regime. Seven RC beams were specifically designed, without and with an external anchorage system, which was carefully detailed to enhance the benefits of the strengthening laminate and counteract the destructive effects of shear forces. All the beams were identical in terms of their geometry, longitudinal internal reinforcement, and concrete strength but varied, to highlight the role of shear behavior, in terms of their internal and external shear reinforcement as well as in their loading test regime. The beams were tested under four-point bending and extensively instrumented to monitor strains, deflection, cracking, load carrying capacity, and failure modes. The structural response of the tested beams has, then, been critically analyzed in terms of deformability, strength, and failure processes that occur under a shear-dominant loading regime. It is shown that with a carefully designed anchorage system, a brittle behavior without yielding of tension steel reinforcement of a flexural strengthened beam can be transformed to a less brittle behavior with yielding of tension steel reinforcement and a well-defined enhancement of structural performance in terms of both deformation and strength. The results presented in this paper should enable engineers to counteract shear failure of externally strengthened beams with little or even no internal shear reinforcement.Key words: carbon fibre reinforced polymer, shear behavior, external flexural strengthening, structural performance.

Impact resonance method for fatigue damage detection in reinforced concrete beams with carbon fibre reinforced polymer

2005 ◽  
Vol 32 (6) ◽  
pp. 1093-1102 ◽  
Author(s):  
Catalin Gheorghiu ◽  
Jamal Eddine Rhazi ◽  
Pierre Labossière
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Fatigue Damage ◽  
Concrete Beams ◽  
Resonance Method ◽  
Rc Beams ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Impact Resonance

This paper reports on the potential of using the impact resonance method (IRM) for detecting fatigue damage in strengthened reinforced concrete (RC) beams. In this experimental program, 1.2 m long RC beams strengthened with a carbon fibre reinforced polymer (CFRP) plate have been employed. The specimens were subjected to fatigue loading under four-point bending for up to 2 × 106 cycles at 3 Hz. The load amplitude was varying from 15% to 75% of the cycles yielding load of the beam. Throughout fatigue testing, the cycling was stopped for IRM measurements to be taken. The obtained data provided information about changes in modal properties, such as, fundamental frequencies and damping ratios. Moreover, the results have shown that the IRM technique was successfully employed in laboratory for detecting fatigue damage in concrete beams strengthened with CFRP laminates.Key words: impact resonance method, modal properties, RC beam, FRP-strengthening, fatigue test, cracking.

Durability and structural performance of carbon fibre reinforced polymer – reinforced concrete parking garage slabs

2009 ◽  
Vol 36 (4) ◽  
pp. 617-627 ◽  
Author(s):  
S. El-Gamal ◽  
B. Benmokrane ◽  
E. El-Salakawy ◽  
P. Cousin ◽  
A. Wiseman
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Laboratory Investigation ◽  
Structural Performance ◽  
Second Phase ◽  
National Capital Region ◽  
Parking Garage ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper presents a laboratory investigation on the durability and structural performance of carbon fibre reinforced polymer (CFRP) – reinforced concrete (RC) slab specimens extracted from the Laurier-Taché Parking Garage (in the National Capital Region, Canada) after being subjected to service field conditions for about 8 years (1997–2005). The laboratory investigation comprised two phases. The first phase evaluated the durability of the CFRP bars, the concrete, and the interface between the two materials by conducting microstructural and chemical analyses on core samples extracted from the slabs. As part of this phase, five CFRP bar samples were extracted and tested in tension to investigate if the CFRP bars experienced any degradation in strength or stiffness. The second phase investigated the structural behaviour of the slabs by testing four slab segments (3.0 m long × 1.0 m wide × 0.2 m deep) in flexure. Test results showed that neither the CFRP bars nor the CFRP–RC slabs have been adversely affected after being in service for 8 years.

Impact resonance method for damage detection in carbon-fibre-reinforced polymer–strengthened reinforced concrete beams subjected to fatigue and thermal cycling

2008 ◽  
Vol 35 (11) ◽  
pp. 1251-1260 ◽  
Author(s):  
C. Ward ◽  
N. Rattanawangcharoen ◽  
C. Gheorghiu
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Resonance Method ◽  
Experimental Program ◽  
Rc Beams ◽  
Structural Health ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Impact Resonance

Much of North America’s civil infrastructure is rapidly aging and, in some cases, exceeding its design life and load. To combat this, the exploration of simple and effective methods for rehabilitation and structural health monitoring has been receiving much attention in industry and academia. This paper reports on the use of the impact resonance method (IRM) for evaluating the structural health of thermal-cycled reinforced concrete (RC) beams with and without externally strengthened carbon-fibre-reinforced polymer (CFRP) pultruded plates. In the experimental program, 1.2 m long specimens were subjected to 55 thermal cycles ranging from +23 to −18 °C. Fatigue loading consisting of up to two million cycles at high and low stress levels was performed. At pre-determined load cycle intervals, the loading was stopped and the IRM was performed on the specimens. Parameters including the appearance of the fast Fourier transform (FFT) spectrum of the specimens’ vibration, modal fundamental frequencies, and dynamic properties were used to assess damage in the specimen. Conclusions were made regarding the use of the IRM in monitoring the health of strengthened and unstrengthened RC beams subjected to thermal and fatigue cycles.

Experimental and numerical study on the effect of repairing reinforced concrete cracked beams strengthened with carbon fibre reinforced polymer laminates

2014 ◽  
Vol 41 (3) ◽  
pp. 222-231 ◽  
Author(s):  
P. Duarte ◽  
J.R. Correia ◽  
J.G. Ferreira ◽  
F. Nunes ◽  
M.R.T. Arruda
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Fracture Energy ◽  
Numerical Study ◽  
Structural Response ◽  
Rc Beams ◽  
Cfrp Laminates ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper presents experimental and numerical investigations on the effect of repairing cracks in reinforced concrete (RC) beams prior to strengthening them with carbon fibre reinforced polymer (CFRP) laminates. The experimental campaign comprised flexural tests on three types of full-scale RC beams with T-shaped cross-section: (i) two reference un-strengthened beams, (ii) two CFRP-strengthened beams previously loaded and cracked, and (iii) two CFRP-strengthened beams, previously loaded, cracked and repaired with epoxy resin. The repair and strengthening techniques consisted of respectively injecting the cracks with epoxy resin and applying CFRP laminates according to the externally bonding reinforcement technique. In the numerical study, the structural response of all beams tested was simulated using the finite element software Atena, which features a smeared cracked model constitutive relationship for concrete. A parametric study was carried out in which the influence of material parameters, namely the fracture energy, on the beams structural response was assessed. Experimental results showed that repairing cracks by means of epoxy injection before strengthening them with CFRP laminates provided a considerable increase of stiffness, but only a slight increase of ultimate strength, as failure was triggered by the debonding of the strengthening system at the anchorage zones. In the numerical study a very good agreement with experimental data was obtained. For the repaired and strengthened beams, such agreement was obtained by increasing concrete’s fracture energy when compared to that of the reference beams.

Hybrid simulation of a carbon fibre–reinforced polymer-strengthened continuous reinforced concrete girder bridge

2017 ◽  
Vol 20 (11) ◽  
pp. 1658-1670 ◽  
Author(s):  
Shizhu Tian ◽  
Hongxing Jia ◽  
Yuanzheng Lin
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Hybrid Simulation ◽  
Simulation System ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Girder Bridge ◽  
Concrete Girder ◽  
Hybrid Simulations

The behaviour of bridge columns strengthened using carbon fibre–reinforced polymer composites has been studied extensively. However, few investigations have been conducted regarding the influence of carbon fibre–reinforced polymer-strengthened columns on the seismic behaviour of reinforced concrete continuous girder bridges. This article details the hybrid simulations of a continuous reinforced concrete girder bridge whose columns are strengthened by carbon fibre–reinforced polymer jackets. In the hybrid simulations, one ductile column is selected as the experimental element, which is represented by a 1/2.5-scale specimen, and the remaining bridge parts are simultaneously modelled in OpenSees (the Open System for Earthquake Engineering Simulation). After combining the experimental element and the numerical substructure, the hybrid analysis model is developed with the established hybrid simulation system. The displacements of the bridge and the lateral force–displacement response of the experimental element in hybrid simulation are obtained. Compared with the results of numerical simulation, the stability and accuracy of the established hybrid simulation system are demonstrated. Meanwhile, the comparative hybrid simulation results of the as-built bridge and the carbon fibre–reinforced polymer-strengthened bridge also prove the effectiveness of the carbon fibre–reinforced polymer jackets’ confinement in the continuous reinforced concrete girder bridge.

Strengthening with Prestressed CFRP Strips of Box Girders on the Chofu Bridge, Japan

2010 ◽  
pp. 21-34
Author(s):  
Masami Fujita ◽  
Terumitsu Takahashi ◽  
Kazuhiro Kuzume ◽  
Tamon Ueda ◽  
Akira Kobayashi
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Box Girders ◽  
Strip Method ◽  
Reinforced Polymer ◽  
Before And After ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Load Tests ◽  
Cfrp Strip

<p>Reinforced concrete (RC) box girders of the Chofu Bridge had been strengthened using tensioned carbon fibre reinforced polymer (CFRP) strip method. Before and after the CFRP application, on-site load tests of the bridge were conducted using a 45 t weight vehicle.</p>

Sign in / Sign up

Export Citation Format

Share Document