Flexural behaviour of reinforced or prestressed concrete beams including strengthening with prestressed carbon fibre reinforced polymer sheets: application of a fracture mechanics approach

2007 ◽  
Vol 34 (5) ◽  
pp. 664-677 ◽  
Author(s):  
Yail J Kim ◽  
Mark F Green ◽  
R Gordon Wight
Keyword(s):  
Fracture Mechanics ◽  
Size Effect ◽  
Carbon Fibre ◽  
Prestressed Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Mechanics Model ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper describes the application of a fracture mechanics model (Hillerborg 1990) to concrete structures, including strengthening with prestressed carbon fibre reinforced polymer (CFRP) sheets. One benefit of the proposed fracture mechanics model, consisting of a unique combined stress–strain response of concrete, is that it includes the size effect of reinforced concrete beams; however, its application and validation have not been fully investigated. The proposed model is reviewed and further developed to cover prestressed concrete beams including a beam strengthened with a prestressed CFRP sheet. To evaluate the model, various approaches such as finite element analysis, a strength-based model, a conventional design method, and experimental results are compared with the fracture mechanics model. The size-dependent parameter (ε1) significantly affects the predicted behaviour of reinforced or prestressed concrete beams, depending on the contribution of reinforcement. Based on the current assessment, ε1 = 0.005 is recommended as an upper limit for normal strength concrete.Key words: carbon fibre reinforced polymer sheet, flexure, fracture mechanics, prestressed concrete beam, reinforced concrete beam, strengthening, size effect.

Behaviour of reinforced concrete beams strengthened with carbon fibre reinforced polymer laminates subjected to corrosion damage

2000 ◽  
Vol 27 (5) ◽  
pp. 1005-1010 ◽  
Author(s):  
Khaled A Soudki ◽  
Ted G Sherwood
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Concrete Beams ◽  
Corrosion Damage ◽  
Corrosion Process ◽  
Reinforced Concrete Beams ◽  
Cfrp Laminates ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

The viability of carbon fibre reinforced polymer (CFRP) laminates for the strengthening of corrosion damaged reinforced concrete bridge girders is addressed in this paper. Ten reinforced concrete beams (100 × 150 × 1200 mm) with variable chloride levels (0-3%) were constructed. Six beams were strengthened by externally epoxy bonding CFRP laminates to the concrete surface. The tensile reinforcements of three unstrengthened and four strengthened specimens were subjected to accelerated corrosion by means of impressed current to 5, 10, and 15% mass loss. Strain gauges were placed on the CFRP laminates to monitor and quantify tensile strains induced by the corrosion process. Following the corrosion phase, the specimens were tested in flexure in a four-point bending regime. Test results revealed that CFRP laminates successfully confined the corrosion cracking, and the total expansion of the laminate exhibited an exponential increase throughout the corrosion process. All the strengthened beams exhibited increased stiffness over the unstrengthened specimens and marked increases in the yield and ultimate strength. The CFRP strengthening scheme was able to restore the capacity of corrosion damaged concrete beams up to 15% mass loss.Key words: CFRP laminates, corrosion, confinement, expansion, load tests, strengthening, bond strength, reinforced concrete.

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.

Strengthening precast-prestressed hollow core slabs to resist negative moments using carbon fibre reinforced polymer strips: an experimental investigation and a critical review of Canadian Standards Association S806-02

2006 ◽  
Vol 33 (8) ◽  
pp. 955-967 ◽  
Author(s):  
Abdelhadi Hosny ◽  
Ezzeldin Yazeed Sayed-Ahmed ◽  
Amr Ali Abdelrahman ◽  
Naser Ahmed Alhlaby
Keyword(s):  
Carbon Fibre ◽  
Prestressed Concrete ◽  
Bending Moments ◽  
Hollow Core ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Negative Moment ◽  
Fibre Reinforced Polymer ◽  
Prestressing Strands ◽  
Negative Moments

Behaviour of precast-prestressed hollow core slabs has been extensively studied when these slabs are subjected to positive bending moments, a practical application typical of hollow core slabs. However, in many projects it may be required to have an overhanging part of the roof to act as a cantilever. In doing so, and using precast-prestressed hollow core slabs, the slabs would be subjected to negative moments, atypical for hollow core slabs. In this paper, the behaviour of precast-prestressed hollow core slabs is experimentally investigated when they are subjected to negative bending moments. A proposed strengthening detail to increase the negative moment resistance of hollow core slabs using bonded carbon fibre reinforced polymer (CFRP) strips is presented. The CFRP strips were bonded to the top side of full-scale precast-prestressed hollow core slabs in the negative moment zone in different configurations. In two of the tested slabs the bond between the prestressing strands and the concrete was initially broken (during casting of the slabs) in the negative moment zone. The slabs with the bonded CFRP strips were tested to failure and the load–deflection behaviour was recorded. The results of the tests are presented and the strength enhancement of the hollow core slabs using the proposed technique is reported. The increase in the negative moment resistance of the CFRP-bonded hollow core slabs experimentally determined is also compared with the CSA-S806-02 prediction for the moment resistance of concrete elements with bonded CFRP strips.Key words: carbon fibre reinforced polymer (CFRP) strips, hollow core slab, flexure strengthening, prestressed concrete, precast slabs, prestressing strands.

scholarly journals Behaviour of Reinforced Concrete Beams Bonded with Glass Fibre Reinforced Polymer and Carbon Fibre Reinforced Polymer Sheets

2020 ◽  
Vol 9 (3) ◽  
pp. 134-138
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Externally Bonded ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

Concrete, a mixture of different aggregates bonded with cement, first developed around 150BC in Rome has been bedrock to the modern Infrastructure. It is used to build everything from roads, bridges, dams to sky scrapers. Strengthening concrete is traditionally done by using steels but the developments in technology in recent decades allowed to use fiber reinforced plastics which are externally bonded to concrete . Such composite materials offer high strength, low weight, corrosion resistance, high fatigue resistance, easy and rapid installation and minimal change in structural geometry. This study investigates the behavior of reinforced concrete beams bonded with fiber composites. A numerical study is conducted to study the behavior of RC beam under Static third point loading. Concrete beam specimens with dimensions of 150 mm width, 300 mm height, and 2600 mm length are modelled. These beams are externally bonded with Glass Fiber Reinforced Polymer (GFRP) sheets and Carbon Fibre Reinforced Polymer (CFRP) sheets. In present study, we examine the performance of reinforced concrete beams which are bonded with GFRP and CFRP sheets with various thicknesses (1, 2 & 3 mm) using ABAQUS in terms of failure modes, enhancement of load capacity, load-deflection analysis and flexural behaviour

Sign in / Sign up

Export Citation Format

Share Document