Flexural behaviour of concrete beams strengthened with prestressed carbon fibre reinforced polymer sheets subjected to sustained loading and low temperature

2004 ◽  
Vol 31 (2) ◽  
pp. 239-252 ◽  
Author(s):  
Raafat El-Hacha ◽  
Mark F Green ◽  
R Gordon Wight
Keyword(s):  
Low Temperature ◽  
Carbon Fibre ◽  
Flexural Behaviour ◽  
Prestress Losses ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Prestressed Cfrp Sheets

This paper presents results of an experimental investigation that examined concrete beams post-tensioned with bonded carbon fibre reinforced polymer (CFRP) sheets and then exposed to either room (+22 °C) or low (-28 °C) temperatures. The primary objective of this investigation was to assess the flexural behaviour of the strengthened beams after sustained loadings at both room and low temperatures. The strengthened beams showed significant increases in flexural stiffness and ultimate capacity as compared with the control-unstrengthened beams. Failure of the strengthened beams was by tensile rupture of the prestressed CFRP sheets. Test results showed that the long-term and low temperature effects did not adversely affect the strength of the beams. Long-term loading and low temperature exposure caused prestress losses in the CFRP sheets. The load–deflection behaviour of the long-term beams was predicted accurately by an analytical model. These results suggest that bonded prestressed CFRP sheets could be used to increase the strength of damaged prestressed concrete girders under extreme environmental conditions.Key words: strengthening, anchorage, low temperature, long-term, prestress losses, sustained load, carbon fibre reinforced polymer sheet.

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

Accelerated corrosion and repair of reinforced concrete columns using carbon fibre reinforced polymer sheets

2000 ◽  
Vol 27 (5) ◽  
pp. 941-948 ◽  
Author(s):  
C Lee ◽  
J F Bonacci ◽  
M DA Thomas ◽  
M Maalej ◽  
S Khajehpour ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Concrete Columns ◽  
Corrosion Monitoring ◽  
Reinforced Concrete Columns ◽  
Accelerated Corrosion ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

An experimental study on the simulation of corrosion in large-scale reinforced concrete columns and their repair using carbon fibre reinforced polymer (CFRP) sheets is presented. Seven columns were subjected to an accelerated corrosion regime, wrapped using CFRP sheets, then tested to structural failure and (or) subjected to further post-repair accelerated corrosion, monitoring, and testing. Accelerated corrosion was achieved by adding sodium chloride to the mixing water, applying a current to the reinforcement cage, and subjecting the specimens to cyclic wetting and drying. Results showed that the CFRP repair greatly improved the strength of the repaired member and retarded the rate of post-repair corrosion. Moreover, subjecting the repaired column to extensive, post-repair corrosion resulted in no loss of strength or stiffness and only a slight reduction in the ductility of the repaired member.Key words: accelerated corrosion, carbon fibre reinforced polymer, composites, corrosion damage, corrosion rate, external confinement, reinforced concrete columns.

scholarly journals An Experimental Study on Concrete Flat Slabs Prestressed with Carbon Fibre Reinforced Polymer Sheets

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yin Shen ◽  
Shaohui Lu ◽  
Fangyuan Li
Keyword(s):  
Carbon Fibre ◽  
Prestressed Concrete ◽  
Utilization Efficiency ◽  
Cfrp Sheets ◽  
Flat Slabs ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Carbon Fibre Reinforced Polymer ◽  
Anchoring System ◽  
Fibre Reinforced Polymer

Carbon fibre reinforced polymer (CFRP) is currently used to reinforce buildings in civil engineering in the common forms of sheets, while the utilization efficiency of a CFRP materials greatly decreased when the CFRP material is directly bonded to the structure because of the lack of the effect of the exertion of a prestress. A paper spool-inspired anchoring method is proposed to overcome the shearing problem in the anchoring system through the friction between layers. Anchoring and jack-up tensioning devices for CFRP sheets are also designed and produced. A prestress is successfully applied to single and multiple CFRP sheets (80% tensioning strength is achieved), thus verifying the tensioning effect of the prestress. Based on these results, prestressed concrete flat slabs were designed with pretensioned CFRP sheets. The corresponding mechanical properties of the concrete flat slabs are tested to verify the feasibility of using CFRP sheets to apply a prestress. The results show that the uniformity of the fibre stress during the tensioning of the CFRP sheet is the key to the success of the application of the prestress.

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